... divided into two types based on their efficiency grade: medium efficiency and high efficiency. They are all two layers structure fabric ... cleaner, etc.l Divided into two types:Medium efficiency: TDY-65D,TDY85D,TDY95D High efficiency : TDY-99A, TDY-99B, TDY99Cl ... Polyester substrate ----as a support for pleatingl Features:Good efficiency, low resistance, energy-saving, environment-friendlyl Usage: mini ...