Kit contains: (2) 1.5" Low Friction Single Pulleys, (4) S Hooks, (1) Roll of String, (20) 10g Masses, (1) 55cm X 37.5cm Backboard with feet Force board grid has a coarse resolution of 5 X 5cm and a fine resolution of 1 X 1cm Clamp on pulleys are constructed of ABS plastic with low friction ball bearings More than enough masses and string to do any arrangement of vectors and forces A great free standing device to introduce forces and vectors to your classroom. High contrast grid made it force configurations easy to see from any angle in class