- 3.5 mm jack
HamiltonBuhl Flex-Phones are nearly indestructible, made from a single piece of EVA foam. EVA foam is safe, non-toxic, BPA-free, soft and an extremely flexible material. Recommended for children ages 3 and up, Flex-Phones feature a snap-on extension band for smaller children - just snap on the extension band for a snugger fit. The extremely clear sound quality ensures young developing ears are protected.