Device is made of stainless steel and its surface is polished.

Including 1 cage, 1 O-shape ring, 1 lock (with keys), 1 spike ring (if you select it), 1 PA piercing pad (if you select it).

Cage has 2 sizes can be selected.

Standard cage length is about 70 mm.

Small cage length is about 60 mm.

Cage inner diameter is about 31 mm. 

O-shape ring has 4 sizes can be selected: 38.5 mm, 43.5 mm, 48.5 mm, 53.5 mm. 

Spike ring has 3 sizes can be selected: 35 mm, 40 mm, 45 mm. These distances are from one spike to its opposite spike as pictures show, not the ring's diameter. The spike ring can replace ordinary rounded ring.

PA piercing pad has a PA hook. PA hook length is about 20 mm, diameter is about 4 mm. 

You can choose them when you order this device.

These sizes may have a little error because it's made by hand.