ITEM NAME:R12 To R134a Fitting Adapter 1/4" Female Flare With O-ring X 1/2" Acme Male New.R12 size: approx. 31mm 15mm. Will convert your R12 vacuum pump or recovery machine. Fitting to accept the center hose of R134a gauges. 1 x Fitting Adapter. Quick, easy connect and disconnect high flow.