... to install diffuser neck size,plastic diffuser with neck adjustable ceiling diffuser hvac plastic diffusers supply ceiling diffuser square ... plastic injection Mould Steel: S45C, P20, 718, 718H, 2738, 738H, NAK80, SKD61, E420, etc. (For Reference)Mould Base: LKM or Self ... Colorthe frame is natural, the adaptoris blackSize250mm*250mm,and different sizes available upon your requirementsFOB Price3.55USD/ ...