ErgoRest Swivel Arm Support
Provides comfortable arm, shoulder and neck support with unrestricted motion. Use this easy clamp-on, swivel, articulating, padded-cup, height adjustable arm support to avoid computer arm fatigue. Studies have shown that muscle tension in the neck and shoulders can be significantly reduced by using an armrest. Arm support with pad is height adjustable and swivels 360 degrees. Clamps onto desk or worksurface up to 2.5" thick. Mouse pad sold separately. Pricing is for one armrest.
More information: http://www.ergonomicresource.com/ergorest.html