J400X & J800X are the special products from the co-extruded POE encapsulating Film series, developed by Sinopoly Materials. J400X is with high transparency, normally for the front side, while J800X is the UV cut-off type, targeting the back side, or front side of HJT cells. Both of them have excellent adhesion strengths to the interfaces, barrier properties, anti-PID performance, and good weatherability, which are perfect for double sided modules.