End plug to seal open sockets of 4-pole distributors to prevent the intrusion of water into the distributor. Of course this sealing is not needed if the plug system is used in dry rooms indoors.
The end plug bridge is needed for current-fed RGB lights (350mA) e.g. LED-Guide 95 as a closure at the final socket of the lights. Without closure, the series connection remains open and the light will not function.