The KMC's 5.5mm MissingLink master link allows you to connect one side of an 11 speed Shimano, KMC or Campagnolo chain to the other. Simply cut the chain to length then clip the MissingLink to each side of the chain, fasten and apply pressure to the chain or use a chain plier to lock the MissingLink in place and installation is complete. These links are 5.5mm and are compatible with any current 11 speed drivetrain.
These master links should be installed new with a new chain and disposed of with the chain, when the chain has reached the end of its life cycle. KMC claims that these 11 speed links are non-reusable and recommend installing a new MissingLink when reinstalling your chain.