Copper plated steel wire. For more information go to www.P65Warnings.ca.gov. Copper plated steel wire. But remember…. SQUEEZ-KLIP™ rings are available in standard sizes as shown or made to your custom specifications. Hog Rings. // -->. Step 4 - Measure the length of the string/paper from the starting point to the mark. Like most hog ring pliers, spring-loaded features and cushioned non-slip grips make it easy to use.