$25 to $50

Set the planets in motion with a flick of your wrist! Build a mechanical model of the solar system including the sun and eight planets (also known ...

Jumpstart your study of mechanical physics by learning all about simple machines and how they're used to make complex tasks easier to do. Through 2...

Build unique robots that are powered by the sun — batteries not required! Using a compact solar panel, these cool little bots harness energy from t...

How cool is it that the mainspring stores energy, then converts it to motion? Discover the physics of potential and kinetic energy and the inner wo...

If you're raising a future James Bond, your young secret agent needs the high-tech help of a location tracker. Hide the transmitter with a valuable...

Stay connected with your fellow secret agents with Spy Labs: Spy Walkie-Talkies. With a range of up to 1.5 mi/3 km unobstructed and 0.5 mi/1 km wit...

Turn your bedroom into your very own planetarium theater! Illuminate a darkened room by casting projections of the stars in the night sky and space...

If your tween or teen has a fascination with all things steampunk - or trains in general - then this kit is for them! Young engineers put on their ...

Construct your air-powered robotic hand that fits like a glove and prepare to blast off! This amazing engineering project uses pressurized air and ...

The wind is one of the most promising sources of clean, renewable energy available today. With this kit, you can assemble a realistic wind turbine...

The power of wind makes them go - and you'll have fun building 6 awesome bots that move without any batteries at all. Easy, snap-together assembly ...