Master Lock Chrome Plated Steel Bent Receiver Pin Lock. It features a swiveling lock head for easy use in tight spaces and 5/8" & 1/2" bent pins to fit 5/8" & 1/2" size receiver holes. The all-weather cover protects the lock key way from harsh elements, ensuring long-lasting performance. It uses Master Lock key blank K1BOX or Ilco blank M1 TV# 320952. Backed by a limited lifetime warranty.