Pedialyte 1L bottles cost about 6 bucks at any grocery store. I started using one at the beginning of the summer and it has become one of my favorites. Medical grade plastic. 1L capacity is what most water purification tabs are design for. Rock solid lid and design. I stood on one just to test it. See picture. No leaks. Never worried about it coming open in the bottom of the pack. Square design means it wont roll off a mountain (i lost a squeeze bottle that way one time many years ago as a scout) Fits in my truck cup holder Clear bottle doesnt stay cool as long as my klean canteen especially in the sun, but i suppose you could do the UV water purification thing if you had too. Ive never tried it just seen it done on one of the survival shows. A insulative pouch would be handy, will have to see if it fits in a maxped pouch. Anyway, nothing fancy just a really cheap sturdy option.