Three number dialing, permanently lubricated, rust resistant inner working parts. Dial cannot be turned when shackle is under tension, safe-guarding combination. Self-locking, automatically disarranging tumblers. Nickel plated steel swivel shackle. Strongdouble wall construction, stainless steel outer case armors heavy wrought steel inner case. 1-7/8 in wide case, 9/32 in diameter shackle, and 13/16 in horizontal shackle clearance.