The advantages of acoustic window handles, First of all design and production is fully Turkish made and registered. The acoustic handles are used both at tilt & turn and turn - only systems, At turn - only systems when the handle is turned 40 the sash opens 1,5 - 2 mm and does not get free from the frame and provides micro ventilation. Provides micro ventilation at tilt & turn systems. At tilt& turn systems when the handle is turned 135 the sash opens at 2 cm - open - vasistas - position and provides safe and continuous ventilation. This special future provides fresh air circulation at homes and offices: healtier breathing all day and night. it removes the inner dry air caused by natural gas and air condition. When the offices and summer houses are not air circulated for long tines, the inner air remains unfresh. By leaving the handle at 45 position, it provides continuous air circulation and removes moist and humidity.