6 Master Lock # 1KA Keyed Alike Padlocks. Same key opens all 6 locks. | eBay
Premier Lock 2-5/8 in. Premier Solid Steel Commercial Gate Keyed Padlock with Short Shackle and 18 Keys Total (6-Pack, Keyed Alike) GAP01X-KA-6 - The Home Depot
Master Lock Hidden Shackle (lot of 6) KEYED ALIKE (60 available keyed alike) | eBay