Two 38 mm spherical lenses; one is a double concave, the other a double convex, each with a focal length of 150mm. When placed together the net focal length is zero. (1-1/2" x 1-1/2" x 1/4"; .005Ib).
Great for optics experiments in the lab or classroom.
This SUPER Erector Construction set is one of the best you'll find anywhere!
This chemistry learning and experiment kit comes with components and chemicals for over 75 amazing experiments!
Check out this high-quality gyroscope!
With this kit, you can conduct 25 experiments to learn how an electric motor converts electricity into motion, and how an electric generator does just the opposite, converting motion into electricity.
Build a model green house and 9 other green energy-related devices with this great kit!
The Y-Ball Magnetic Puzzle is the perfect creativity tool for innovators, artists, engineers, writers, students, and you!