Vintage Presto Combination Lock Hardened Shackle PRESTOLOCK USA

This is a vintage Presto Combination lock, made in the USA by PRESTOLOCK. It has four dials and has a hardened steel shackle. The combination will be provided with the lock, and there is a technique for resetting the combination that can be found online. It has patent number 3766758, which was issued in 1972. According to the patent, "the invention relates to combination padlocks, and is more particularly directed to improvements in combination padlocks of a type including means for setting or changing the combination to a combination of one's own personal choice."