Our grandaughter, Julianna at 9 months LOVED this Tri Chew! Another great product designed by Debra Beckman, MS, CCC-SLP. Constructed of a medical grade chewy, resilient material. Designed with ridges, bumps and swirls on each end to simulate the various textures of food used for chewing. Sensory input is provided for the lips, gums, and tongue through the textured sides. The material provides comfort for a teething baby. The triangular shape keeps the Tri Chew from being inserted too far into the mouth and makes it easy for little ones to hold. Not recommended for aggressive chewing. The TRI CHEW is recommended from birth to two years. Sanitize by scrubbing with mild soap and water. The XT is tougher than the standard Tri-Chew .