This is the Build Your Own Mousetrap Powered Vehicle Kit from Doc Fizzix.
FEATURES: Easy-to-wind and snag-free string release system eliminates tangles
and snags for increased performance
Uses lightweight low inertia DVD/CD layers for wheels
INCLUDES: One balsa wood strips (18" x 3 x 3/16")
Two brass tubing axles (6 x 3/16")
One brass tubing lever arm (12" x 1/8")
Four CD/DVD wheels
One balsa wood strips (12" x 3 x 3/16")
Eight rubber DVD/CD spacers
Four metal thrust washers
One Victor mousetrap
Three zip lock axle hook
36" Kevlar string
REQUIRES: CA glue and needle nose pliers
SPECS: Length: 18" (457.2mm)
Width: 3" (76.2mm)
COMMENTS: What is a mousetrap powered car and how does it work?
A mousetrap-powered racer is a vehicle that is powered by the energy
of a wound up mousetrap's string. The most basic design is that
one end of a string is tied to the tip of a lever arm that is
attached to the mousetrap's "snapper arm". The other end of the
string has a loop that is designed to catch a hook attached to a
drive axle. Once the loop is placed over the axle hook, the string
is wound around the drive axle by turning the wheels in the opposite
direction to the vehicle's intended motion. As the string is wound
around the axle, the snapper's lever arm is pulled closer to the
drive axle causing the mousetrap's spring to wind up & store energy.
When the drive wheels are released, the string is pulled off the
drive axle by the mousetrap causing the wheels to rotate.