The Periscope
The Teetering Penguin
The Safe
The Combination Lock
The kaleidoscope
The Merry Go Round
The Sundial
The Catapult
The Chaotic Pendulum
The Jet Car
The Boomerang Wheel
The Rain Stick
The Math Balance
Staying-Balanced Combo set
Measuring Weight & time Combo Set
combo-Forces & Energy
combo - Color & light
combo - Codes & Riddles