Versaflo TR-371+ Replacement Filter Cover 3M Versaflo TR-371+ replacement filter cover compatible with the TR-300+ series of Powered respirator systems. The replacement cover will protect the filters and pre-filters that fit the 3M Versaflo Powered Air Turbo TR-302E+. FEATURES and BENEFITS: Replacement filter cover Compatible for TR-300+ series, Versaflo Powered Air Turbo TR-302E Protects filters and pre-filters