An arrow lock is a lock with standard dimensions used by the United States Postal Service for mail carriers to access collection boxes, outdoor parcel lockers, cluster box units, and apartment mailbox panels. Arrow locks are unlocked through the use of a corresponding arrow key. Arrow locks are also referred to as "Master Access Locks"[1]
- ^ "3-3 USPS Master Access Lock". about.usps.com. Retrieved 2021-06-21.