The Master Lock No. 312 Covered Laminated Padlock features a 1-9/16in (40mm) wide laminated steel body for superior strength and a 1in (25mm), 3/8in (10mm) diameter hardened steel shackle with molded cover for excellent cut strength and weather resistance. A blue, weather resistant thermoplastic cover provides protection against environmental elements such as moisture, dirt & grim while a non-rekeyable 4-pin W1 cylinder offers strong pick resistance.