Product Description: ROKR 3D Wooden Puzzle-Model Building Kits -DIY Movement Assembled Toys-Brain Teaser Educationa l and Engineering for Boys Girls Aged 14+,When Christmas, Birthday Characteristics: Product Name:Perpetual Calendar 3D Wooden Puzzle Brand: ROKR ?Theme: Perpetual Calendar Material: Wood The Number of Pieces: 27 pcs Age: 14+ Finished Size: 17.5 x 9 x 14 cm Product Feature: ?WoodenPuzzle?This is a perfectly designed DIY kit that requires your hands-on work to complete. This mechanical wooden puzzle toy uses precision laser cutting of high- quality plywood, which is safe and convenient. ?PuzzleDesign?This Beautifully Designed Perpetual Calendar is allow the calculation of the day of the week for a given date in from year 2018 to 2040.Surprise your family, friends and colleagues with this mechanical Perpetual