Fixed T-Arms Solid Steel Heavy Duty Replacement Arms. These arms are ideal for heavier duty use as they have no movable parts. The solid steel construction insures many years of use. The mounting hole pattern for under the seat is 1.25" x 2.25" that is very common in the industry. The top has a welded plate and has 2 mounting holes for the pads / tops / caps. The spacing between mounting holes is 4" to center. Listing is for 1 pair.