Dual Film Test Cartridge for OX-TRAN 2/28 & AQUATRAN 3/38, Cell area 50 cm2, Truseal flush ring at the perimeter ensures a leak-free seal every time increasing accuracy and repeatability, Top/bottom cell arrangment, Max sample thickness 20 mil (0.5mm) forUse for OX-TRAN 2/28 and AQUATRAN 3/38