I have both bottles and the optimus is slightly widers but hardly noticeable. The mouth of the bottle is quite different though. I can use my optimus stove with a optimus or msr bottle however the optimus bottle has a wide rim on the mouth of the bottle and my msr pump doesn't seal on the optimus bottle.

I've never seen a fuel bottle that big, and these certainly don't go to that size.

All manufacturers of these type of fuel bottles use a similar inside coating. As long as you use it for fuel, e.g., alcohol, kerosene, & white gas, you'll never have a problem. Problems occur when people store acidic fruit juices in them & then drink the juice. At one time Sigg used a coating that could be used safely for multiple liquids. This was the red anodized bottle, not the plain aluminum one.

In general, I would say yes as long as it's never had fuel in it. I would be a bit concerned about the epoxy coating inside, but I don't really know what the effects of that would be, if any. Maybe check with Optimus.I wouldn't recommend it.Use plastic bottles for water. They are more water friendly & less expensive.

Optimus multi-fuel stoves have a burner designed to use petroleum based fuels. Therefore, you cannot use alcohol-based fuel. It is recommended that you use chemically pure gasoline (not automotive gasoline) or high-quality kerosene. Under no circumstances should you handle fuel near a lit stove or in your tent.Use a funnel with a filter when filling the bottle so as to avoid dirt and foreign bodies getting into the fuel. Never mix different kinds of fuel. Empty the bottle entirely before putting in a different fuel.GASOLINEIt is often very easy to get hold of gasoline, even though thequality is variable. Chemically pure gasoline is preferable.Ordinary automotive gasoline contains additives which willcontaminate your stove and are hazardous for your health. Ifyou have to use automotive gasoline, use unleaded gasolinewherever possible. Gasoline is highly flammable and preheatingoccurs quickly. However, gasoline is also very volatile andburns explosively.KEROSENEKerosene has more or less the same energy value as gasolinebut is considerably less of a hazard in terms of fire. It is usedall over the world and is easy to get hold of. You can oftenfind kerosene in places where you would not find other fuels,such as in food stores. Preheating takes slightly longer withkerosene than with gasoline and is slightly sooty, but there isnot much of a risk of explosion. Kerosene also requires you toclean the burner more often.It is recommended the use of kerosene, as it is primarily designedfor use in stoves and heaters. It is NOT advise the use oflamp oil or fire lighting fluid (charcoal lighter).NOTE: In harsh cold, there is a risk of kerosene solidifying,which makes the stove unusable.DIESELDiesel is somewhat similar to kerosene, but preheating takesslightly longer and it produces even more soot. We recommendthat you only use diesel as last option. If you do so, use dieselfor cars. Avoid marine diesel entirely. One positive aspect ofdiesel is that it can be found all over the world.Visit www.optimus.se for more information about fuels.It will also work well with alcohol.

MSR Stove disclaimer:Use MSR® fuel bottles only. Non-MSR fuel bottles may leak fuel, resulting in fire and injury.The threads on these bottle do share the same thread count as those produced by MSR, but these threads seem to be aligned at different angles. Though this bottle may work, this will most certainly cause threads to be striped & some leaking may occur.I think that is not quite right. The threads are the same, thats not a problem, no damage will be done to the threads. However, the lip around the top of the msr bottle is thiner than sigg, optimus etc.; so the pump gasket fits better on the msr. If you are careful putting the pump on it will work fine, but the msr bottle is a better option if you have an msr stove.