Interface Shield provides a convenient way to make connections from microcontrollers to sensors. Shield plugs directly on top of and adds two BTA (analog) and two BTD (digital) sockets, be used with SparkFun RedBoard, also works with Intel Galileo
Simple Atwood Machine, include Apparatus and 2 pulleys connected by a rod, 1.75inch plastic pulleys connected to a 3inch rod, Overall length is 8.25inch, Two pulleys are connected by a metal rod.