HIPLOK uses a four tier security rating system featuring Basic, Medium, High and Maximum levels Maximum security D lock, noose style chain and security tie combine for maximum potential Maximum security D lock, noose style chain and security tie combine for maximum potential 14mm hardened steel shackle with 10mm hardened steel chain Perfect for E bikes, cargo bikes, and other non standard frames Rated Gold by Sold Secure`s independent lab testing 3 coded replacement keys D lock is 3.35` x 5.90`