We stopped putting the water level marking numbers on the plunger because we were concerned that they encouraged the use of the plunger in microwave ovens and we just do not know what effect microwaves have on the life of the rubber seal.
FAQ
We stopped putting the water level marking numbers on the plunger because we were concerned that they encouraged the use of the plunger in microwave ovens and we just do not know what effect microwaves have on the life of the rubber seal.