No. 13 in detailed image drawing.
Connects M-8823113 - 3 inch Mueller Milk tank valve to M-8825995 quick connect
Replacement o-ring part number M-8801962
Made in USA by Paul Mueller Co
Related Items;
M-8825995 New Style Quick Connect
M-8801962 O-ring
M-8826008 Adapter connects to Mueller M-8823113 -3 inch milk tank valve (this item)
M-8826007 Adapter connects to Mueller M-90601 -2 inch milk tank valve