Solid, virgin PTFE, standard taper joint inserts and Duran® flange inserts.

• For use with stainless steel, flat heads
• Bottom reverse thread on joint inserts includes PTFE collar and FETFE O-Ring
• Top outer [ST] joint that matches glass [ST] inner joints
• Flange insert matches glass Duran flange
• O-Ring not included for Duran® flange insert

These joints are for use with stainless steel, flat heads. The top of the insert features an outer standard taper joint that matches glass standard taper inner joints. The bottom is made with a reverse thread and includes a PTFE collar and FETFE O-Ring for attaching to the flat heads. Top of insert is also machined to accept certain joint clips. For use with flat stainless steel lids.