The Astro eco telescopic letterbox system range is specifically designed to increase the safety and security of occupants against fire and is particularly suited to multiple occupancy residential buildings. The Astro eco telescopic letterbox is a stylish, ABS framed, telescopic letterbox with metal flaps fitted with a high performance intumescent liner around the telescopic sleeve section. Acoustic and thermal performance features include brush pile draught excluders, integral sound dampening bumpers and a fully sealed backplate. During a fire the intumescent liner rapidly expands and seals off the letterbox opening, preventing the spread of fire and smoke whilst maintaining the integrity of the fire door assembly. Cut out required is 241mm x 57mm for standard size letterbox and 274mm x 57mm for commercial size letterbox. Both sizes have a black ABS frame, except the SSS which has a silver frame. The letterboxes are available in Satin Aluminium, Chrome Plated, Stainless Steel, Polished Silver, Polished Brass or Polished Gold letter plate flaps.