1.25 receiver trailer hitch lock is great for locking your bike rack or trailer to the hitch. Hitch lock has a 1/2 diameter and works for all 1.25 receivers. Inside width 1-0.625 overall length 5. Comes with 2 Keys. Covered key opening. Easy key insertion and removal. Weather resistant lock. Product Features:Pin Diameter 1/2, Inside width 1-5/8, overall length 5 (Class I and Class II)Patented, pick-proof screw and lock securityFlush locking designMade in the USA