1/4" FNPT M style Kwik change couplers will interchange with all manufacturers who comply with the dimensional requirements of military specification MIL-C-4109. M style couplers have a basic flow size of 1/4" and offer up to 300 PSI. Complete with a Buna-N Seal. These M style couplers have a brass body and sleeve with air flow of 40 SCFM.