8221D - Yale 8200 Series Medium Duty Deadbolt (Double Cylinder with Dimple Key) Standard: ANSI / BHMA A156.5.2003 Testing Cycles: Tested up to 100,000 cycles Materials: - Chassis: Steel - Latch and Bolt: Zinc - Strike: Steel / Brass / Stainless Steel - Cylinder Housing: Brass / Steel - Round Plate: Brass / Steel Backset: 60mm / 70mm Door Thickness: 35~50mm Function: Residential, commercial and institutional applications. Anti-Sawing Insert: Hardened Steel Cylinder: Solid Brass 5-pin tumbler cylinder No. of Keys: 3pcs of nickel plated brass key Finishes: Polished Brass (US3), Antique Brass (US5), Antique Copper (US11), Chrome Plated (US26), Satin Stainless Steel (US32D) 8211D - Yale 8200 Series Medium Duty Deadbolt (Cylinder and Thumbturns with Dimple Key) 8421D - Yale 8400 Series Medium Heavy Duty Deadbolt (Double Cylinder with Dimple Key) 8421 - Yale 8400 Series Medium Heavy Duty Deadbolt (Double Cylinder)