• Product Dimensions ‏ : ‎ 7.5 x 5.25 x 3.75 inches; 1.46 Pounds
• Manufacturer recommended age ‏ : ‎ 9 years and up

The screw, another of the  simple machines, converts a circular motion (the turning of the screw) into a linear motion. It also lets you amplify the force a great deal, since turning the screw only moves the end of the screw a small amount. This classic wooden model offers children a basic concept of the laws of physics. Desktop sized.