GE-312A only have a plastic magnet inside the body, it have less component, so it will be very stability. GE-312B is piston flow switch, it could installed by any postion.
Teflon PTFE material is available, but MOQ should be more than 300units
Contact: Mr.Robert
Phone: 0086-13166369204
Tel: 400-852-8332
Email: sales@ayt.hk
Add: Building 17 &22, No.2928, Chuan Zhou Highway, Shanghai, 201319, China