These are the real military issue hydration system carriers in green/black, used in excellent condition, with a brand new aftermarket 2.5 liter BPA free bladder and hose we put in so you are drinking from a good, fresh clean system.
These are simple, durable and compact systems that do what they need to- keep you hydrated- in a package that doesn't have a bunch of unnecessary stuff. And if you have a pack that is hydration system compatible these packs are slim enough to go inside without having to take the bladder out of the carrier so you can quickly switch between using it in the pack or standalone.
Some of these will have labels marking them as MOLLE, some will say ILBE, but they are the same system. Manufacturers vary on the carriers based on who had the military contract, some are Camelback, some are Specialty Defense along with several over vendors.