Specification : Product name : adjustable seat armrest Material : plastic metal Integral Skin Foam Color : black Width : 5.6cm/2.2 Length : 35.5cm/14 Adjustable range : 90 Side : right / left Placement on seat : right / left Recommended mounting height : the distance between seat cushion and the underside of the armrest is 11cm ( or up/down 2cm according to you need) Installation : 1.Open the cover of the seat back. 2.please sit on your seat and make the mark on the position where is the most comfortable to you. 3.drill two holes on the mark you have made. 4.fix the armrest mount to your seat with screw .(screws not include) 5.open a little hole on the sponge, then take the axis out of the sponge. 6.As for the cover, it is the same with last step. 7.Fix the armrest to the parts from the outside, and fix the screw. 8.Put on the lid. Package included : 1 x seat armrest