Practice hand/eye coordination with the ECR4Kids Twist and Lock Nuts and Bolts. Match the over-sized nuts and bolts by shape or color and twist them on. The 64-piece set includes four shapes on both the nuts and bolts: triangle, square, plus sign and a hexagon. All shapes have rounded edges for safety and come in four colors: blue, green, yellow and red. To clean, wash pieces in the sink with a clean sponge or rag, soap and warm water.