The movement trays are made of transparent plastic, meaning that they will complement your miniatures regardless of the basing scheme that you've used on them. Each set of bases tessellates so you can put together large units of miniatures. There are eight different designs of movement tray (two of each design are supplied) for added variety. 8 movement trays (of 4 designs) hold 3 miniatures, and 8 movement trays (of 4 designs) hold 2 miniatures – Citadel miniatures on 40mm bases are usually supplied in sets of 3 or 5 models, meaning you can easily combine 2- and 3-model trays to carry them.