Food grade silicone nipple - More durable, will not deform, heat and corrosion resistant. Flat bottom glass material - Safe, can sterilize under high temperature. Curve shapre bottle - Ergonomic design fits baby hand. PP Anti-Dust Cover - Baby can drink without worry. Artistic design - PUKU cartoon non-toxic ink printed, baby will love it.. Anti-slip handle - Baby can self learn drinking. Thick Silicone Base - Match with the handle and further protect the base of your glass bottle.