Here's a puzzle with a real twist! This set consists of six pieces plus the board/tray, but four of those pieces are actually made of two pieces connected together which can be twisted to create different shapes. This unique feature makes the puzzle even more fun and challenging, and greatly expands the creative possibilities. The connected pieces twist easily but will not come apart (yes, we tried it!). The puzzle pieces are made of solid rubberwood with water-based stains, so their colour will not chip or flake off. It also comes with a board/tray made of formed rubberwood sawdust reclaimed from the manufacturing process, and a 12-page booklet with over 60 challenging forms to create, from simple to complex. The board/tray measures 18 cm (about 7") square.