STUDCOLLAR-SILICONE-INDIVIDUAL is a firm silicone white ring. The ID is 38mm and the ring does have a bit of 'give' and it will stretch a little. The wall thickness is 5mm and the ring is 10mm deep.

STUDCOLLAR-SILICONE-INDIVIDUAL is a firm silicone red ring. The ID is 38mm and the ring does have a bit of 'give' and it will stretch a little. The wall thickness is 5mm and the ring is 10mm deep.

STUDCOLLAR-SILICONE-INDIVIDUAL is a firm silicone black ring. The ID is 38mm and the ring does have a bit of 'give' and it will stretch a little. The wall thickness is 5mm and the ring is 10mm deep.