The Office Master OM5 is best known for a recline system that responds to the person sitting in it. That idea still defines the current OM5 Evolved range, but the models and details have changed since the original OM5-B, OM5-G, and extra-tall versions described in older reviews.
This guide covers the current family, what separates its backrest choices, and the fit questions worth answering before you configure one. It is a guide to the manufacturer’s design and specifications, rather than a claim that we have tested every configuration with every body type.
What Body-Activated Motion actually does
The OM5’s self-weighing mechanism responds to your weight and how you load the backrest. As you recline, the seat and back work together rather than relying on a conventional tension knob that you repeatedly turn to find the right resistance.
That simplifies one part of setup. It does not automatically choose your seat height, seat depth, lumbar position, or armrest height. Those still need to suit you and the desk. “Self-weighing” describes the recline mechanism, not a chair that fits every person without adjustment.
OM Seating also uses the term Virtual Pause for the way the mechanism can settle into a supported position. It should not be confused with a conventional lever-operated lock that fixes the back at selected angles. Buyers who strongly prefer that type of lock should compare the two experiences before deciding.
The current OM5 models
OM5: mid-back Polyflex
The standard OM5 Evolved uses a flexible polymer backrest and an upholstered seat. It is the starting point for shoppers who like the clean profile of the original OM5 and want a task chair with responsive movement.
The current listing adds a bilateral lumbar system, a field-removable seat, and 2.5 inches of seat-depth adjustment. The seat can be positioned for leg length while the back support is tuned separately. A mid-back label does not make it a petite chair by itself; the seat-height and depth ranges still need to fit your measurements.
OM5-EX: high-back executive Polyflex
The OM5-EX offers a higher Polyflex back for users who prefer more upper-back coverage. It retains the self-weighing movement and the adjustable seat-depth approach of the standard Evolved chair.
It is a current model in its own right, not simply a new name for every older OM5 executive or extra-tall configuration. When replacing an older chair, compare its measurements and selected options with the current specification rather than treating the model names as interchangeable.
OM5-MH: high mesh back
The OM5-MH brings a mesh back to the Evolved family. It offers a different feel and more airflow at the back than the polymer versions, while keeping an upholstered seat and Body-Activated Motion.
Back material is a preference, not a comfort guarantee. Some users like the flexibility of Polyflex; others prefer the contact and ventilation of mesh. The useful comparison includes where the back meets your body, how it feels during recline, and whether the seat fits at your usual working position.
Stools and gaming configurations
The range also includes OM5-TS, OM5-EX-TS, and OM5-MH-TS stools for elevated work surfaces. These require a workstation-height check and suitable foot support; they are not standard desk chairs with a different appearance.
The OM5-XP gaming chair is another distinct configuration. Its upholstered styling and available options deserve their own comparison rather than being assumed to come with the basic task model.
How to configure the chair around your work
Seat upholstery can change the chair’s feel, appearance, and cleaning requirements. An upholstery grade is a pricing category; it is not a simple ranking in which every higher grade lasts longer. The actual material, abrasion specification, cleaning instructions, and intended setting are more useful criteria.
Arms should support the forearms while allowing relaxed shoulders and close access to the keyboard. Height adjustment is useful, and width, pivot, or fore-and-aft movement may help depending on the desk and your tasks. The features vary by arm kit, so an adjustment shown on one configured chair should not be assumed to be included on another.
Caster choice belongs in the configuration too. Carpet and hard-floor needs differ, and specialized casters can affect the chair’s height or rated capacity. The manufacturer lists the current OM5 work-chair series at 350 pounds, but the final rating should be checked for the selected components.
Who is the OM5 a good candidate for?
The family is worth comparing if you want movement through the workday and prefer a recline that responds to your weight without a conventional tension adjustment. It can also be useful where people share a chair, provided the seat and arm adjustments are still reset for each user.
It deserves a closer trial if you prefer a very firm, fixed back angle or have a specific fit requirement outside the configured dimensions. A chair with more manual controls may suit that preference better. The appeal of the OM5 is its particular movement, rather than having the largest possible number of knobs.
Older OM5 chairs and replacement parts
If you already own an OM5-B, OM5-G, BEX, GEX, BXT, or GXT, use the model and production label when asking about parts. A current Evolved seat or accessory should not be assumed to fit an older chair. Photos of the label and the part in question help identify the right replacement.
The OM5 family carries a limited structural warranty, with separate coverage and exclusions for upholstery, foam, and consumable parts. “Limited lifetime” does not mean every component is covered indefinitely. The manufacturer’s current warranty and the purchased configuration are the relevant references.
For current pricing and options, visit the OM5 product page or contact our team with your fit requirements.
