Tie Down Engineering 4-Lug Hub/Spindle End Unit for Build Your Own Trailer Axle System - 1350-Lb. Capacity Per Hub, Model# 80115 4-lug hub/spindle end unit Fits 1 1/2in. x 1 1/2in. tube (Item# 124991) and spindle/flange set (Item# 124993) Sold individually, 2 end units required per axle