These are replacement teeth designed to replace the teeth in a Nerf Roughcut 2x4 if the original ones break. The central hole must be drilled out with a 3mm drill bit.
To replace them, first open the gun (colors may vary depending on which version you own): Remove the 3 screws in the charging handle first and remove it. Next, loosen all the screws in the main body of the gun and open it up. (be careful with the small orange part and the spring in the tactical rail at the top of the rifle as it can fly off and disappear).
You may want to take pictures at this point to help you put it back together.
Inside you should see the two pistons connected to the barrel at the front. The two pistons are connected to the main mechanism. This consists of a pinion (flat gear) connected to the charging handle, two pinions (one large and one small) and another pinion connected to the pistons. There is also the trigger.
The product was designed by
Spartacus1812
