Brackitz Pulleys & Cranks module is an add-on educational construction kit to the Brackitz Structures module (sold separately). Students can explore how to make things that will haul, lift, slide and move up and down. They can even build zip lines that stretch more than 4 feet in length! This kit is designed specifically for the classroom supporting up 4-6 students at one time. Includes 25+ free online lessons and activities. A reusable storage bin keeps all the pieces together and organized.