BOX COUPLERS are predominately utilized in laboratory applications. 

ESI-510
Five Stub Box Coupler - BJ77 (3 lug) Connector
ESI-510
ESI-5210 / ESI-5310
Other internally terminated 5 stub couplers
ESI-5210 / ESI-5310
ESI-530
Five Stub Box Coupler - BJ157 Connector
ESI-530
ESI-550
Five Stub Box Coupler - BJ77FL (4 lug) Connector
ESI-550