Milton Hose Anchor plugs into 3/8" hose, recommended for use with Milton's patented signal hose. These anchors are specifically designed to be plugged into the non-bell end of a signal hose to hold the hose in place, and each achor's dual outlets also allow it to connect two separate lengths of hose. The use of a Milton hose anchor is recommended, though not required, for each driveway bell or chime in use, but anchors are sold separately and individually.