Product details
- Brand
- Herman Miller
- Color / finish
- Slate Grey back; Alpine seat; Fog arms
- Product type
- Ergonomic polymer-back task chair
Description
This Mirra 2 uses the exposed TriFlex polymer back rather than the fabric-faced Butterfly option. Its pattern of openings and flexible structure let the back respond to movement while giving the chair a crisp, open appearance. The Slate Grey back, Alpine seat and pale frame make it a distinctive choice for a bright workspace.
The seat is AireWeave suspension, with adjustable depth to help match different leg lengths. Adjustable arms, lumbar support and the tilt limiter add control over the working position. The product’s reference to a fixed TriFlex back identifies the back construction; it does not mean the chair cannot recline.
Features
- TriFlex polymer back: provides a perforated support surface without a fabric back covering.
- Adjustable seat depth: lets you change the usable front-to-back seat dimension.
- Suspension seat: keeps the seat visually light and allows air through its open material.
- Adjustable lumbar support: is part of the configuration stated in this product’s title.
- Tilt limiter: sets the permitted recline range for your preferred desk posture.
- Adjustable arms: help position the arm support around typing, mousing and other tasks.

Specifications
- Back surface
- TriFlex polymer
- Seat depth
- 16.2–18 in
- Color pairing
- Grey + Alpine finish
| Model | Mirra 2 |
|---|---|
| Back | Slate Grey TriFlex polymer |
| Seat | Alpine AireWeave suspension |
| Arms | Fog adjustable arms |
| Seat depth | Adjustable; approximately 16.2–18 in |
| Lumbar support | Adjustable, as specified in the listing |
| Recline | Harmonic tilt with tilt limiter |
| Casters | Hard-floor/carpet type |
Choose the back surface that suits your workspace
TriFlex is a practical option if you prefer the feel and appearance of an exposed polymer back. It does not have the padded feel of an executive leather chair, and its suspension seat is different again from a foam cushion. Think about these contact surfaces alongside the adjustment list when comparing chairs.
| This TriFlex configuration | Perforated polymer back with a light Alpine suspension seat. |
|---|---|
| Butterfly configuration | Adds a fabric-faced back surface; a different Mirra 2 product option. |
| Seat fit | Use the adjustable front edge to leave space behind your knees while keeping contact with the backrest. |
| Recline setup | Adjust tension before using the tilt limiter; the two controls serve different purposes. |
Common questions
Does “fixed TriFlex back” mean there is no recline?
No. TriFlex describes the back support construction. This product includes the Mirra 2 tilt mechanism and a tilt limiter, so the chair can move into a supported recline.
Is this an all-mesh chair?
The seat uses AireWeave suspension, while the back is perforated TriFlex polymer. That combination differs from both an all-mesh chair and a Mirra 2 with Butterfly back.
Are the arms fixed?
No. Adjustable arms are specified for this Slate Grey/Alpine product. The fixed-arm Mirra 2 is a separate configuration.
Does it include forward tilt?
A tilt limiter is specified; the additional forward seat-angle option is not confirmed for this item. Do not infer that option from general Mirra 2 videos or other listings.
Product information & sources
Color and supplied adjustments follow this catalog item and its gallery. The TriFlex polymer back has been distinguished from Butterfly suspension; manufacturer-family options are not automatically treated as included. Herman Miller: Mirra 2 back options and dimensions; Herman Miller: Mirra 2 adjustment guide; Herman Miller: Mirra 2 product sheet. Reviewed September 2026.
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