Description Specifications Literature Accessories Description Parker Seal Nut and Washer ThredSeal Kit for 70 Series Go Switches. 3/8" Zinc plated steel with nitrile rubber (standard) washer. State of California Proposition 65 WARNINGCancer and Reproductive Harm - www.P65Warnings.ca.gov. Product Specifications Product SpecificationsMaterial:Zinc Plated SteelDimensions:3/4" Literature & Docs Product Details Accessories GO Switch 77-13526-A2 Model 77 Limit Switch GO Switch 77-13528-DCA Model 77 Limit Switch