Pentair In-Floor (A&A) Gamma Series 4 Adjustable Flow Pop-Up Head – Light Gray 2322024 in 1 Adjustable Flow Nozzle with a Stronger Spring That Pops Up Fully Even on Variable Speed Pumps The Gamma Series 4 Adjustable Flow Pop Up Head from Pentair In Floor (A&A) is the direct upgrade to the Series 3 and it drops right into your existing Gamma 3 and Gamma 4 collars, so replacing a worn head takes minutes, not a system overhaul. A redesigned spring and larger locking tab fix the two things that frustrate pool owners most: heads that won't