Track 1 picece. Length 1.3m, one of forming aluminum platform, anode treatment, has two groves, a metric scale, and two T-slots on both side. Plunger Cart 1 piece. A Spring-loaded plunger has three cocking positions, accessory tray, two tapped holes, bumpers, low-friction wheels. Collision Cart 1 piece. Has magnets, accessory tray, two tapped holes, bumpers, low-friction wheels Cart Masses 3 pieces. Designed to be placed on the upper tray of a cart. Adjustable Feet 2 pieces. Adjustable End Stop 2 pieces. Harmonic Springs 4 pieces. Friction Block 1 pieces. Has two different surfaces (wood and felt). Extra Pulley with Clamp 1 set. Low-friction, low-inertia. Angle Indicator 1 pieces. Spring Cart Launcher 1 set. Experiment Guide. Experiment CD.