ADAM L Yes, I am very pleased with my purchase! I have had it for a couple of years now and it has been very durable. Before this one, I owned a couple of MSR-branded bladders that all ended up getting leaks in them. As for your question, all of the Platypus bladders are true to size. If you are concerned with it fitting, you could perhaps go to an REI and see if the size of the bladder relative to your pack is acceptable.

BRANDON C The Platypus in the link is a 1L bladder. I actually now prefer a bladder with a little more protection around the reservoir as they are more resistant to punctures. It would be worth the extra money for you in the long run. Perhaps the Platypus Insulator Hydration Pack? If the Columbia Mobex pack has a separate compartment for the bladder this may not be an issue for you, but as you pack items in you would have to be careful not to cause any holes.

REMI D I have been using camelbac system since 1996 - the year they came out and after trying the platypus for 5 minutes I'm going back. Everything is worse, mouthpiece, hose, bladder. The worst is that if it's not in the right position you can't get all the water out. Returning mine.

EMILY R It's actually 1.8L, which I like. The nice part about it is that the place where the hose attaches is the same size as a regular soda bottle so you can cap off the bladder really easily before you want to attach the hose. The bladder takes some time to dry, but I've found that it's better than the softer bladder that don't have as much structure to them. Hope this helps~

MICHAEL M they come in 1.0, 1.8, 2.0 and 3.0 liters (the 3.0 liter is on sale) I have the 2.0 liter Hoser (and lots of other Platypus bottles)- the quality is top notch and they are lighter than most other equivalent sized bladders (or bottles). no complaints w/ mine at all as far as the 3.0 liter fitting the Mobex, you could always call Columbia