Po Selected Espresso Cup with Silicone Ring Set, Porcelain Silicone White, 4.7 x 4.7 x 6.5 cm, Set of 4, Yellow/ Red/ Blue/ Green/ Black by OPP Innovative Design, each mug size; 1.75 " diameter x 2.75 " tall Alternative solutions with functional features Silicone ring to help you to hold it tightly Mug has a two-walled structure to protect your hands from hot drinks Set of 4 and gift boxed