Aeroflow inline radiator hose fillers are designed to be used in a radiator hose to provide a remote coolant system fill. Machined from 6061-T6 billet aluminium it accepts a large 38mm radiator cap. Machined with 2 x 1/8" NPT ports for water temp or pressure gauges with one port featuring a straight 5/16" (8mm) barb fitting included. This filler features internal threads into the main body of 1-1/4"-20 which will allow the use of the an Water Neck Adapters and Radiator Hose Adapters both sold separately. This filler includes the 1-1/4"-20 to 42mm barb adapter. Available in silver or black anodized finish.