 The expense of this proposition as well as the unpopularity of the connector itself among technicians led the locking feature to eventually be dropped, and locking connectors are no longer manufactured.The locking connectors that are still found occasionally in installations or spare parts bins are often referred to as "Union Connectors", though the Union Connector brand now features only standard non-locking stage pin connectors.Since their introduction, stage pin connectors have been available in 20 A, 30 A, 60 A, and 100 A varieties, with the higher-current connectors being not only far larger in size but also with a different pin configuration for ground, neutral and line.