Type P163A or P164A auxiliary remote release units allow the internal valve to be closed from a location other than the primary control point (Type P650 or P651). Pulling the auxiliary release handle trips the release mechanism on the primary control to close the internal valve.Type P164B is a release assembly primarily for use with Type N550/N551 ESVs that uses 50 ft / 15 m of cable housing. Type P164C - an Auxiliary Remote Release without cable is also available.