These RaceQuip seat mounting brackets are Aluminum construction and can be used to mount the seat between 2 inches and 5 inches in height. The brackets allow for a 0 Upright seating position up to a 30 Layback position. Aluminum seat mounts are hard coat anodized and weigh 3lbs. Note that this set is undrilled on the base. Boxed as a pair of rails for one seat.