Sleeved Letter Plate A stylish, adjustable telescopic sleeved letterbox. An all-in-one letter plate solution for your front door. This letterbox assembly has an identical appearance from inside or outside the door hence no need for an additional internal letter tidy. Supplied in two parts, an aperture is created in the door and the two parts locate together forming a tunnel effect. Extending inner sleeves allows fitment to a variety of door thickness. To suit doors up to 70mm thick. Please note to make this a fire rated FD30 product you need to order INT1050 Intumescent Pack with a lead time of 5-10 working days.