30-617-2.5  2.5mm  306172.5 2550B Calrad  Locking dc power Coax Plug 2.5 (ID) x 5.5 (OD)

This Locking DC power coax plug has a 2.5mm inside diameter and 5.5mm outside diameter. The 30-617-2.5 has a 9.5mm long connector. Insert into 30-616 jack and twist clockwise to lock. Cable opening .14"