Master Lock Commercial Magnum Locks Feature a Laminated Steel Body with Stainless Steel Cover and Chrome-Platted Shackle. Magnum Commercial Locks Include the Nos. M1 STS (M1KDSTS, M1KASTS, M1STSMK, M1LFSTS, M1KALFSTS, M1LJSTS, M1KALJST) and M5 STS (M5KDSTS, M5KASTS, M5STSMK, M5LFSTS, M5KALFSTS, M5LJSTS, M5KALJSTS) Series Magnum Padlocks.