The Master Lock No. 6621 ProSeries® Weather Tough® Covered Laminated Padlock features a 2-1/8in (54mm) heavy steel body to withstand physical attack and a 1-1/8in (29mm) tall, 5/16in (8mm) diameter hardened boron alloy shackle for superior cut resistance. Padlock is available with our without cylinder to key at your facility with a choice of 22 Key-in-Knob keyways to match this padlock to your security door locks. The exclusive cover protects from water, ice, dirt and grime.