Household, disposable cylinder with a soft tube, the weight of the cylinder (830-930 grams) is a foam exit 30-40 liters.
2. There should be a marking with foam: the manufacturer, production date and shelf life are indicated. If it is absent, then you should think about whether it makes sense to buy such a product. Indeed, when the marriage is detected, while using the cylinder, you just have no one to make a claim.