Hamilton makes three families of retractable housings. The Retractofit is our basic manually retractable housing. It is only available with G1-1/4" process connection and has no other options. The Retractex family offers both manual and pneumatic versions with a variety of materials and process connections that can be selected depending on the application. Finally, the RetractoMaster is specifically designed for use with the ChemoTrode refillable sensors.