The Opener & Seal Set is designed to create a secure exit point in your tent or shelter for the external air intake tube of the large external air stoves. Made of durable stainless steel, it is easy to install and built to last. 

Includes: Stainless steel rings x2, stainless steel sealing disk x1, silicone sealing ring x1, screws x4, wing nuts x4

Specs:

Diameter of sealing disk: 5.25"

Inside diameter of rings: 3.75"