The first few times cage meets Sergeant Rita Rose Vrataski in the battle field he just has normal everyday exoskeleton suit:
But then, in the scenes after he meets Sergeant Vrataski he has these special guns that fire from his back pack,
The suit from side on clearly showing the guns,
An image clearly showing no guns,
Taking into account that he always is taken into combat by the ship that Master Sergeant Farell commands, and they fit him with a suit, how did he get this special suit?