Spartacus Leathers Cock Rings Nitrile 5 Pack Rainbow. In response to the popularity of their rainbow pack of rubber cock rings, they have introduced a 5 pack in nitrile. Colorful, flexible nitrile cock rings are the perfect skin safe solution for those with rubber allergies, and they offer a firmer experience than our rubber rings. These amazingly durable cock rings are made of 100% skin-safe nitrile, the same material used in hospital gloves. Nitrile cock-rings are strong yet flexible, snapping back to shape after each use. Nitrile is a latex-free, strong and flexible material. Because it is latex-free, nitrile is a preferred cock ring material for men with rubber allergies. And not to worry, they are compatible with silicone & water-based lubes! Set includes 5 1.25 inches rings. One each colors: Black, Blue, Purple, Red and White. Spartacus Leathers A Passion For Quality page 21.