Illustrate:
It's aluminum and PP-R material band,one connected to pipe or elbow,another one connected whorl.

Features:

1) size:20*1/2, 25*3/4, 32*1a stndard for choicing.

2)Rust , leakproof , defroming and airproof difficult, what is using comprehensive.

3)Corrosive, fungus and germs stressing.