The TeacherGeek hand reamer is an essential tool for STEM | STEAM and Maker activities, projects and more. Use it to easily change the holes in TeacherGeek components from a press fit (where dowels stay stuck) to a loose fit (where dowels can spin or slide). Excellent for crafting wheel axles, vehicle chassis and geared mechanisms. Bright purple and perfect for little fingers, reamers are an essential component for any young inventor, engineer or artist's tool kit. Durable, safe and built for innovation.