Material: Top Quality 304 Stainless Steel, Never Rusty.
1. Cage length about 50mm.
2. Inner diameter is about 32.5mm.
3.Opening and closing arc-shaped ring inside .diameter;38mm,41mm,51mm.57mm, Can choose one (please leave a message for us which size would you like).
Note: If there is no requirement, random send 51mm ring.