ive seen this asked in a similar manner before. I want to find a very slim line hydration pack with a side zipper for a pistol pouch. preferably its own zippered area. I am going to address this now because i am only looking for input on the packs. i know a Firearm on the hip is worth 2 in a bag. i wear a climbing harness 8+ hours a day. due to that on body carry does not work. i will not be taking my pack off other than to fill the bladder up. ideally i would like just a hydration pack with the pistol pouch nothing more. i want it as small as possible with an internal retention system. will be for a Glock 30. any input is much appreciated.