This Chuck Key Holder securely attaches chuck key 48-66-3280, 48-66-2110, 48-66-3480, 48-66-3080 or 48-66-3240 to the cordset of your drill which has chuck 48-66-0240, 48-66-0795, 48-66-0797, 48-66-0805, 48-66-1360, 48-66-5185, 48-66-1381or 48-66-2100 on it.