lets start with the canteen, it's a british pattern 1958 water bottle...it has been the same style since 1958 and comes with a plastic mug which clamps/fits over the top...it also has been cheaply copied by a few countrys and companys..you can tell the real from the fakes by the cheap molding and no makers stamp also the plastic mug has metal rivets rather than plastic rivets on the real ones..most of the newer bottles have a OSPREY makers mark...the metal cup on the bottom of the water bottle is a new item on issue to the british army its called a "crusader mug" it comes in both stainless steel and teflon coated..before this mug the british troops never had a metal mug only the plastic one and had to use thier messtin to heat food up...the stainless steel is issued to the british forces...the "cooker" or stove nests on the bottom of the mug and can use hexamine tabs,trioxane or that new jellied fuel now on issue to british forces...back in the day the water bottle was carried in the brit. canvas(a tight fit) p-58 water bottle carrier now its carried in the new nylon PLCE carrier(lots of room)as th pouches are cut big...also now carried in chest rigs and vest pockets....to answer your question its a good strong water bottle holds 1 ltr. i have a few real ones and use them all the time...i like brit. kit....vince g. 11b inf.