Built for demanding environments, this ergonomic Sierra – Big and Tall – 24-7 Office Chair with a Comfort Cut Out delivers round the clock support and durability for task intensive offices.
A low Comfort Cut Out at the rear of the seat and back provides added clearance at the hips and lower spine, creating space for broader bodies or large utility belts. A 9 ply tapered seat shell and dual density foam make this chair rated for 24-7 use.
The back panel uses rugged black ballistic polyester for added wear resistance, and the seat and back are upholstered in your choice of hand-sewn eco-friendly fabrics.
Via our Comfort Cut Out at the rear of the seat and back, which provides added clearance at the hips and low spine.
Seat boxing, back seat panel, out-back and bottom-back cutout in black AIM 1200D ballistic polyester for ultimate protection and durability.
28'' black nylon reinforced base.
26F comes standard as added dual density foam for long-term use and support.
70MM heavy-duty Casters
Includes a dual-density foam-padded, heavy-duty, 11 layer seat shell for added comfort, and long term durability and support.
14BB - Includes extended back bar for greater support, longevity, and durability.
Protective edge guard to keep chair fabrics safe and enduring, even with intense use.
Comfortably and easily accommodates up to 500 lbs.
Via our Comfort Cut Out at the rear of the seat and back, which provides added clearance at the hips and low spine.
Seat boxing, back seat panel, out-back and bottom-back cutout in black AIM 1200D ballistic polyester for ultimate protection and durability.
28'' black nylon reinforced base.
26F comes standard as added dual density foam for long-term use and support.
70MM heavy-duty Casters
Includes a dual-density foam-padded, heavy-duty, 11 layer seat shell for added comfort, and long term durability and support.
14BB - Includes extended back bar for greater support, longevity, and durability.
Protective edge guard to keep chair fabrics safe and enduring, even with intense use.
Comfortably and easily accommodates up to 500 lbs.
The RFM Seating Sierra MP 24/7 Heavy-Duty Office Chair is engineered for reliability, comfort, and durability where it matters most — in high-demand work settings and for users who require robust ergonomic support. Proudly manufactured in the USA, the Sierra MP is built to support continuous use around the clock, all while delivering comfort, adjustability, and long-lasting performance.
Designed for environments where tolerance for discomfort simply doesn’t exist, the Sierra MP 24/7 Office Chair combines premium ergonomic features with heavy-duty construction to help users stay supported, focused, and productive through every shift.
Work happens in many places — control rooms, operations centers, dispatch areas, medical facilities, security hubs, and anywhere a chair may be in constant use for 24 hours a day, 7 days a week. The Sierra MP is purposefully engineered for these demanding environments, where downtime isn’t an option and comfort cannot be sacrificed.
With its heavy-duty build and Comfort Cut-Out seat design, the Sierra MP reduces pressure points and promotes better circulation — key factors for users who spend extended periods seated or for workstations that are shared among many users.
This chair supports people where it counts: at the lower back, hips, and legs — providing dynamic support that adjusts to the body rather than forcing the body to adjust to the chair.
One of the standout features of the Sierra MP 24/7 Office Chair is its engineered Comfort Cut-Out seat design. This thoughtful innovation helps relieve pressure on the thighs and promotes improved circulation — especially important in continuous use settings. By reducing discomfort in critical contact areas, the Sierra MP empowers users to stay comfortably seated longer without the fatigue typically associated with prolonged sitting.
The cut-out seat also helps maintain a healthier posture by encouraging the user’s pelvis to remain properly aligned, supporting the lower spine and reducing the risk of slouching or strain over time.
The Sierra MP is built to perform under pressure — literally. Its frame, mechanisms, and base are designed to withstand heavier use and higher load demands than standard office chairs. Whether in 24/7 call centers, medical triage stations, or security operation centers, this chair delivers consistent and reliable performance day in and day out.
Key aspects of its heavy-duty design include:
Reinforced structural components
Durable weight-support system for larger users
High-capacity base and robust caster options
Long-life foam and upholstery engineered for heavy wear
Each element of the Sierra MP is selected and assembled with longevity in mind — because in high-traffic settings, reliability isn’t just desirable — it’s essential.
Just because a chair is built for durability doesn’t mean it should compromise on comfort. The Sierra MP 24/7 Office Chair offers a suite of ergonomic adjustments that help users fine-tune their seating position for optimal support, including:
Adjustable lumbar support
Height-adjustable seat
Tilt tension controls
Arm adjustments (where applicable)
These adjustments help accommodate a wide range of body shapes and seating preferences, empowering users to modify chair settings to fit their own comfort needs rather than forcing a fixed posture that can lead to fatigue or strain.
A major strength of the Sierra MP chair is its ability to deliver true heavy-duty comfort without feeling bulky or industrial. Designed with bigger bodies in mind, the chair supports larger users with confidence — combining reinforced capacity with ergonomic comfort.
Whether you need seating for plus-size team members, shared workstations, or high-use spaces where strength is a priority, the Sierra MP offers peace of mind backed by thoughtful engineering and rigorous performance standards.
The Sierra MP 24/7 Heavy-Duty Office Chair is equally at home in:
24/7 operations and dispatch centers
Healthcare and emergency services
Control rooms and monitoring hubs
Security command centers
Industrial offices and logistics areas
In any setting where comfort, durability, and continuous performance are paramount, the Sierra MP rises to the challenge — giving users a seat they can trust through every shift and every task.
Like all RFM Seating products, the Sierra MP 24/7 Heavy-Duty Office Chair is manufactured in the USA, reflecting decades of design expertise and commitment to quality craftsmanship. By controlling the manufacturing process from start to finish, RFM ensures consistent performance, durable materials, and reliable ergonomic function across every chair.
This focus on quality means your seating investment delivers long-term value — reducing maintenance, increasing comfort, and supporting the people who rely on their seating day after day.
The Sierra MP 24/7 Chair is more than a chair — it’s a solution for challenging work environments and users who demand strength, comfort, and resilience. Built for continuous use, plus-size support, and ergonomic comfort, it is the chair of choice for workplaces that never slow down.
Not all heavy-duty office chairs are built the same. Many chairs labeled “big & tall” or “24/7” focus primarily on weight capacity, often at the expense of real ergonomic comfort. The Sierra MP 24/7 takes a more thoughtful approach — combining true heavy-duty construction with ergonomic design that supports real bodies during long, demanding shifts.
Most heavy-duty chairs:
Emphasize load rating over pressure relief
Use thick padding without addressing circulation
Can feel rigid, bulky, or overly industrial
Often lack refined ergonomic adjustability
The Sierra MP difference:
Designed specifically for continuous 24/7 use
Built to support plus-size bodies comfortably, not just safely
Incorporates a Comfort Cut-Out seat to reduce pressure and improve circulation
Balances durability with ergonomic nuance, not stiffness
Provides adjustability that allows users to fine-tune comfort over long shifts
The result is a chair that doesn’t just hold up — it actively supports the user hour after hour.
Standard 24/7 chairs often:
Are built for long hours, but not necessarily larger bodies
Rely on dense foam that can trap heat and pressure
Offer limited seat design variation
Prioritize mechanism durability over user comfort
Sierra MP stands apart by:
Pairing 24/7 durability with pressure-relieving seat engineering
Using the Comfort Cut-Out to support pelvic alignment and leg circulation
Offering ergonomic features that adapt to both long hours and diverse users
Maintaining comfort even in shared or rotating-shift environments
This makes the Sierra MP especially well-suited for dispatch centers, control rooms, healthcare operations, and any environment where multiple users rely on the same chair.
For organizations investing in heavy-duty or 24/7 seating, longevity isn’t just about materials — it’s about how well a chair supports the human body over time.
The Sierra MP excels because it:
Reduces pressure points that lead to fatigue
Supports circulation during long seated periods
Maintains comfort across multiple shifts and users
Holds up structurally in high-demand environments
Feels supportive rather than restrictive
This makes it a smarter investment for:
24/7 operations and dispatch centers
Emergency services and healthcare environments
Security and monitoring stations
Plus-size users needing real ergonomic support
Shared workstations with rotating staff
If you need a chair that simply meets a weight rating, many options exist.
If you need a chair that supports real people through real work, around the clock, the Sierra MP stands apart.
Built for demanding environments and plus-size bodies, the Sierra MP doesn’t just endure long hours — it supports them.