The Air Conditioner AC Long Window Slider Bracket Extension works with the window slider to extend the length of the original window slider. This part does NOT come with installation instructions. This original Delonghi Air Conditioner 20 In Window Slider Extension originally shipped with the following Delonghi devices: NF90B PACC100 The size of this part is 19-7/8 x 3-3/4 x 1 . This is a true Delonghi part! This item is NEW! Don t see your model number? Send us a message as we are happy to help!