The Master Lock No. 6271 ProSeries Hidden Shackle Padlock features a 2-7/8 in. (73 mm) wide reinforced die cast body that withstands forcible attacks and a 3/8 in. (9 mm) diameter boron alloy shackle. The Lock body conceals the shackle, defeating attempts to pry and cut. Ideal for transportation, vending and industrial applications, the high security, rekeyable 6-pin cylinder with spool pins is virtually impossible to pick. Features: ProSeries Padlocks are designed for commercial/Industrial applications Lock body conceals shackle - defeats attempts to pry and cut 2-7/8 in. (73 mm) wide reinforced die cast body withstands forcible attacks 3/8 in. (9 mm) diameter boron alloy shackle High security, rekeyable 6-pin cylinder with spool pins is virtually impossible to pick