Easy lock is a compact, tool-free automatic locking mechanism. It is an essential accessory for plug-in boxes (PIU) in busbar applications. Easy Lock combines operation, automatic lock, and status indication in one device. The lock can be installed or removed in just three seconds, giving it an installation efficiency of about six times higher than other products. The visible green indicator lets users know if the PIU has been securely fixed. A universal accessory, easy lock can be adapted to PIUs of different sizes and weights for high production standardization and reduced costs.