Spartacus Leathers Cock Gear Metal Cock Rings. 1 1/4″ Nickel Cock Ring. Steel is an excellent alternative for those with nickel allergies. Spartacus nickel cock rings make a striking visual statement with their silver color. Made using Nickel. Single metal cock rings, your choice of sizes, in nickel or black. Weighs 0.26 pounds. Spartacus A Passion For Quality Catalog page 26. Made in the USA. New images added February 3, 2013.