With these durable shot glasses made of PP material you are completely ready for the future. The reusable shot glasses can be washed in the dishwasher up to at least 20x and that is why they are reusable, durable or whatever you want to call it. The major advantage of the PP material is that it does not splinter. So should the glasses fall on the floor and you want to mash them to a pulp; you won't succeed. This prevents dangerous situations and the glasses are child-friendly, which is nice! These glasses therefore fit in all reusable programs of festival providers where PP is used and you are therefore not tied to their glassware.