A hoop lock including a shackle and a crossbar, with the shackle having a pair of legs extending from a body portion, and each of the legs having a foot including a tip with a non-circular cross-section. The cross-bar includes a housing having a pair of foot-receiving openings and a pair of tip-receiving openings substantially aligned with foot-receiving openings. The tip-receiving openings are configured to matingly engage the tips such that the tips are rotationally coupled to the housing.

A padlock, which is capable of remaining functional in even very dusty, watery or otherwise difficult conditions is disclosed. In addition, there would be reason for forming the protection level of the padlock to be selectable and updatable as needed to be even better. A protective cap is provided with a gasket and possibly gasketed latch elements.

A hoop lock including a shackle and a crossbar, with the shackle having a pair of legs extending from a body portion, and each of the legs having a foot including a tip with a non-circular cross-section. The cross-bar includes a housing having a pair of foot-receiving openings and a pair of tip-receiving openings substantially aligned with foot-receiving openings. The tip-receiving openings are configured to matingly engage the tips such that the tips are rotationally coupled to the housing.

A gun trigger-locking device which is configured to be manually installed on a gun with a trigger-blocking member disposed behind the trigger to prevent the gun from being fired. The device includes a data receiver, a data memory and a logic device for determining whether data received by the receiver is the same as data stored in the memory. If a data match is indicated, the logic device causes an electromagnetic device to move a locking member to an unlocked position, permitting the trigger-blocking member to be manually removed from the gun so the gun can be fired. A separate electronic key is provided to transmit unlock data to the data receiver of the trigger-locking device. This unlock data may be a password, a long pseudo-random number or biologic data identifying the gun owner or some other person who is licensed or otherwise authorized to fire the gun.