Captain O-Ring - Power Pressure Washer O-Rings for 3/8" Quick Coupler, EPDM (10 Pack) [1/2" o-Rings to fit 3/8" QC Fittings] EPDM Rubber is compatible with many chemicals and cleaners O-Rings measure 1/2" Inside Diameter x 0.100" Thick. These 1/2" o-rings are designed for 3/8" Quick Connect fittings found on many pressure washer wands and hoses. Tear and abrasion resistant Compatible with temperatures up to 300F (for higher temperatures, check out our Viton o-rings) Comes in a package with 10 o-rings. Manufactured and warrantied by Captain O-Ring LLC