The kbk wz. 2002 BIN is a prototype Polish assault rifle.
The BIN was a prototype created by Wojskowa Akademia Techniczna in 2002 as an attempt to convert the well-proven FB Beryl weapon system into a bullpup form; it was not intended for mass production or production of any kind. The prototype BIN served as the basis for a computer generated design known as the BIN-21, which was used as the basis for the Kbk wz. 2005 Jantar.
The weapon is based on the FB Beryl. The BIN is a fully-functional prototype with a provisional wooden stock.