Bumper mounts under the chassis with 4 screws.
Most of the Pro bumpers are made of thinner nylon 0.096" to keep the weight down for the 2wd buggies.
The Racer2 for the B5 will also fit the B4.
This listing comes with the following for Associated B5 rear motor:
- One TBR Pro Front bumper
- Lifetime warranty
A perfect fit and made of a great flexible plastic to absorb the impacts. Best part is that it's made in the USA!