*Knee Tilt Mechanisms: We highly recommend the knee tilt mechanism for those whom it is stature and use appropriate. There are several drawbacks to the Knee Tilt mechanism; please read the below paragraphs carefully before you choose this option. Knee tilt is not available with taller (7, 8, and 10 inch) cylinders. 

*Good Things about the Knee Tilt mechanism: Since the pivot point is right behind the knees, it allows you to gently rock while your feet remain flat on the ground. You dial the spring tension to suit your weight and more or less float. Remember, increased movement is preferable to static postures. This type of ongoing gentle movement can have therapeutic effects for people who would otherwise work in rigid postures for hours on end. The mechanism allows for both locked and free float mode. When the phone rings while you are in the free float mode, and you shift the weight of your arms back from the keyboard, the chair will float back into a reclining position. Without effort or adjustment to the controls, you have moved to a different and more comfortable posture. This is the beauty of the knee tilt.

*Shortcomings of Knee Tilt mechanism: 

1. Even though they are rated at 275, we don't recommend these mechanisms for people above 250. The springs just don't seem to have the "umph" for long term use for people above 250 pounds.
2. These chairs do not have seat depth adjustment; the seat is set at about 16.5" (see chair fitting information). At this seat depth the chair will accommodate most people between 5' 3" and 5' 10' very nicely.

*The Fring is a footrest / foot ring that spans two legs on the chair. It's especially useful for people who are a little too short for their work surface height and would like an alternative position for resting their feet besides the footrest. Ergonomically speaking, multiple positions and movement are usually preferable to constricted or single-position static postures.

*NeXtep® is not only a foot rest, but also wide, stable platform that can be used as a step up to the chair, supporting up to 400 pounds. Casters allow for easy movement with the chair.

*OES are the “Oversized and Extra Soft Arms.” Previously we had recommended the cheaper gel arms, which are just slightly softer in comparison to regular chair arms. But based on overwhelming customer feedback, we now suggest upgrading to the OES arms. Customers tell us, and we agree, that the OES arms are very soft, very comfortable and offer a better broad arm resting surface. We've yet to hear from a customer who was disappointed with the optional OES arm rests.

*Upholstered Back: The back shell component will come upholstered with the selected fabric.

*Brake In (C4) casters will stay put when the user sits down and roll when the user stands up.

*Brake Out (C3) casters will roll when the user sits down and stay put when the user gets up.

*Specify Soft Casters (urethane) on hard surface floors like tile, wood, or concrete.

†18" black plastic footring, 20" chrome footring, NeXtep® 10" H-leg with casters and NeXtep® Combo 8"/10" with casters can only be ordered with a 8" cylinder (L4) or 10" cylinder (L5).

‡NeXtep® 8" with casters is not available with a 3" cylinder (L1).

§The knee-tilt (3) option is only available with the 3" cylinder (L1), 4" cylinder (L2) or 5" cylinder (L3).

*Cylinders, your height, and the height of your workstation:

You can visit our "choosing your chair" page to help you decide which chair best suits you. Choosing your Chair.

If you are shorter than 5' tall and you have the good fortune to work at surface and or keyboard platform that is at the correct height, consider the 3" cylinder. If you work at regular height surfaces and your feet do not touch the floor, consider the Fring, and make sure you use a good footrest that allows you to rest the weight of your lower legs and feet in a forward position.

If you are over 6' 3" its usually a safe bet to use a 7" Cylinder instead of a 5"; also you'll want to consider the 800 seatpan.