Master Lock 3516 Replacement Keys: 2 Keys Enjoy a FREE 1 cc Packet of Super Lube Multi-Purpose Synthetic Grease with Syncolon with your purchase — a must need for lubricating your old locks when using new keys! Example Master Lock 2001-4200 Key Shown MUST BE LOCK CODE FROM KEY OR ORIGINAL PACKAGING, NOT THE PADLOCK Master Lock 3516 Replacement Keys: 2 Keys. Enjoy a FREE 1 cc Packet of Super Lube Multi-Purpose Synthetic Grease with Syncolon with your purchase — a must need for lubricating your old locks when using new keys! Example Master Lock 2001-4200 Key Shown. MUST BE LOCK CODE FROM KEY OR ORIGINAL PACKAGING, NOT THE PADLOCK.