The FF-209 is a one-time use airsoft projectile designed to create a powerful sound on impact and shrapnel from the rear of the projectile. It is made in two parts - the tip of the projectile is made from a rubberized bouncy material (which can be reused), whereas the bottom is made from a biodegradable plastic that will be consumed on impact. The sound cartridge used is a 209 primer (100-110 dB).