The Zurn Wilkins 860XLFT Resilient Seated Ball Type Test Cock with SAE Flare Fittings is installed on backflow preventers as a test port for attaching a differential pressure gauge. The RK18-860XLFT is a standard test cock repair kit containing four 1/8" test cocks with SAE flare fittings compatible with 1/4" - 1" backflow preventers.