The big size is suitable for the early stage of full finger grip; The middle size is suitable for patients whose fingers have certain grasping function but with poor flexibility; The small size is suitable for patients with better finger functions, and it is used for exercising finger flexibility. Very smooth, no glitch, not scratching the hand Made of solid wood, free from harmful substances The base is a composite board,uniform distribution, the same depth, the stick will not be skewed. Size: Approx. Wood Board S: 18 x 14 x 2 cm / 7.08 x 5.51 x 0.78 inch M: 24 x 20 x 2 cm / 9.44 x 7.87 x 0.78 inch L: 34 x 2 cm / 13.38 x 11.02 x 0.78 inch Wood Stick S: 7 x 1.5 cm / 2.75 x 0.59 inch M: 8 x 2 cm / 3.14 x 0.78 inch L: 9 x 2.5 cm / 3.54 x 0.98 inch Number of Sticks(Random Color): 20 Pieces Material: Wooden Specification: Through a series of actions: use different fingers to fit, pull out, insert a wooden stick, change the hole, pull out, insert it, pick up the designated stick, enhance the control of the fingers and upper limbs, and improve hand-eye coordination. Package Includes: 1 Piece Training Wood Board 20 Pieces Wooden Sticks(Random Color) Note: 1.Please allow 1~3 cm error due to manual measurement, thanks. 2.Due to the difference between different monitors, the picture may not reflect the actual color of the item. Please understand, thank you.