The DORMA BTS84 is a double action floor spring which has been specially developed for the aluminium and toughened glass door industries. This unit is intended to complement our internationally acclaimed RTS concealed overhead door closer by giving the shopfitting industry the option of a DORMA quality floor spring designed for their particular purpose. The BTS 84 has many of the features of the other DORMA BTS closers with the addition of reduced depth and an array of accessories designed for the aluminium door fabricator and toughened glass door manufacturer. Certified manufacture to ISO 9001.