The contents of the kit I recieved are exactly as advertized but the following may help the mat is a 21 x 15cm plastic laminated information sheet with ring sizes, kiln firing temperatures, shrinkage diagram and other useful info on one side and a grid of geometric lines on the other. The instructions are 2 A4 sheets folded into a booklet with plenty of illustrations and instructions showing all parts of the kit in use the packets of PMC also come with a manufacturers instruction leaflet with similar but more general info. The clean-up tool is an extra-firm foam brush, size 0 with a flat chisel edge the stainless steel brush is the size of a toothbrush and the sandpaper is a a 6 x 7 cm square of what feels like P1000 wet-and-dry paper. the two cubic zirconia I recieved were a round cut purple, 6 mm dia, and a red cut 4 x 6 mm oval, which the instructions assure me can be fired with the silver. The roller is a section of clear plastic tubing with 2 mm thick walls so it looks quite durable the spacers are clear plastic that feels like a shatterproof ruler so I dont think they will break too easily either. The mystery rubber block appears in the instructions to be used as a support while sandingburnishing. Other items the booklet mentions that arent included are a cup of water and a straw for shaping the promised pendant and a butane torch or kiln for firing. Also mentioned are a burnisher, tumbler andor polishing mop for finishing beyond the brushed finish if desired. So this kit contains everything it promised and almost all youll need