Glow in the dark Nite Glow activited by the exposure to light Patented US 29896946 Thumb-grip handle with opening on bottom New design allows beer steins to be easily stacked for better storage 38 reduction in plasticusage compared to 14 oz beer stein Stackable stein allows for compact shippingand reduced shipping costs -38 savings in shipping per minimum piece order Durable plastic Top shelf dishwasher safe Hand wash only