Master Lock No. S31RED Zenex™ Thermoplastic Safety Padlock features a 1-3/8in (35mm) wide plastic red body and a 1-1/2in (38mm) tall, 3/16in (5mm) diameter Marine grade 316 stainless steel shackle for superior corrosion resistance. Ideal for corrosive environments, lock body stands up to chemicals, temperature extremes and is UV stable. Designed exclusively for Lockout/Tagout applications the durable, lightweight, lock body is easy to carry and padlock features high security, reserved-for-safety cylinder with key retaining, to ensure padlock is not left unlocked.