Tools4Bikes Velomount Fork Mount 100mm quick release axle and skewer, 15mm and 20mm thru axle-adapters included Fully compatible with the vast majority of road and mountain bikes right out of the box No extra parts needed for thru-axle compatibility, uses your bike's 15mm or 20mm thru axle Flat mounting plate with two 5/16 diameter holes allows for quick bolt-on installation into truck beds, bed channels, trailers, Van's, even 2 x 4's Center post has wide 3/4" square center opening for cable locks or tie downs