Gator II office chair arm rests offer plenty of length to support the whole forearm. The bottom attachment screw holes include both 4" and 5.5" center to center spacing, they will mount on top of many kinds of chair arm posts. These armrest pads are 3" wide and 12" long. Gator II has slightly softer cushioning than Gator I. This offer includes one pair of office chair arm pads. Specify a quantity of 1 for 1 set.. 2 for 2 sets.. etc. Satisfaction guaranteed, if product does not meet your needs, just return within 30 days for a refund (shipping is not refundable). If you have any questions, just call toll free.