pulleys
knex education intro to simple machines levers and pulleys
knx1072 br strong features strong br li intro to simple machines levers and pulleys li li build 8 different replicas of real world models one at a time li li include building instructions with real life photos and key facts for each model li li ideal mechanical advantage li li product type general creative li li connection tools pegs li li material wood li li age range 8 12 years 12 years and up li li gender boy li br strong dimensions strong br li overall product weight 3.2 pounds li
knex