BTS 84 is a double action floor spring, specially developed for aluminium and toughened glass doors with weights of up to 100 kg. It provides concealed installation and a minimal floor recess depth. It features hydraulically controlled closing and backcheck. Closers offer spring strength of EN 2, 3 and 4. Closing ranges are, valve 1, 130-0 degrees sweep and, valve 2 increases closing speed between 130 and 20 degrees. Optional hold-open enables door to be held at 90 or 105 degrees. A universal cover plate is supplied in stainless steel or satin brass and interchangeable spindle inserts are available to suit site conditions. High mechanical efficiency enables easy door opening and operation is smooth and thermoconstant.