inkyy I was not sure what the dimensions are so I included another picture for you with my 22mm kayfun to give you a better idea of dimensions. Due to the fact it is a telescopic mod it is a little more chunky, but the topcap looks perfect with a 22mm attie but if you look (zoom in) at the picture i actually think a 23mm attie like the squape would be at home on this thing.