Carapace Armor does not take up a spot (I merely wanted your armor type posted in GEAR in case I ever need to verify what sort of protection you have should an engagement be going against you). As such, things that make sense you can pack a double of (two Frags for example). Things that wouldn't make sense (Nano-Fiber Vest, Thermal Goggles, etc.) you only need one of so don't waste your extra slot.