This is a pair of OEM Meyer Crossover Relief Valves for the old style (Part# 15556) Valve Block. You are buying both pictured. These are quickly becoming OBSOLETE since Meyer discontinued the E-47, E-57, and E-60 units recently, not sure when Meyer will run out of these. Get them while you can. These will not work on any other angle blocks! The angle block these are for was standard in the 1970's. I had two 1979 E-47 units in for a rebuild last month, one had this old style block, and one had the newer style block. Click on Related tab for just the Springs. As of October 2018 we now only offer the Springs.