This is a Rocket Car Chassis Weight from PineCar.
FEATURES:
- Increases car speed...the heavier your racer, the faster it goes!
- Incremental weights allow racer weight adjustment, even on race day!
- Can be modified to fit any racer!
- Expertly replicate the underbody of real cars!
- Instructions provided on package.
INCLUDES: (1) Chassis Weight
REQUIREMENTS:
SPECIFICATIONS: Approx. Weight: 2.25oz
COMMENTS: 
- Check your local rules for maximum racer weight (usually 5oz) and minimum clearance (usually 3/8" from racer bottom to track).
- Adult supervision is recommended when modifying weight.
- You will need one of the metal-cutting blades from the Racer Shaping Tools if you are modifying the chassis to fit your racer
- All PineCar, PinePro, and Revell wood blocks and accessories are legal for your Official BSA Pinewood Derby race - except the Show Wheels and Titanium Axles. In a sanctioned race all contestants must use the same wheels and axles.
Used with permission, Copyright 2017 Revell-Monogram. Copyright 2017 Brey Corp. t/a Hobby Works.