Designed by a speech-language pathologist, ARK's Probe is an excellent tool for oral motor treatment and sensory development. The rectangular tip has a softer feel to be gentle on the gums, lips, tongue, and cheeks. It's bumpy on one side, striated on the other, and smooth along the edges. These textured surfaces provide tactile input, awareness, and sensation. Use it to stimulate the gums, palate, cheek, and tongue through stroking and by applying pressure. It can also be used to provide targeted tactile cues for articulation or oral motor exercises. Made in the USA, medical grade, FDA compliant, no lead, phthalates, PVC, BPA, or latex. Dishwasher-safe. This therapeutic tool should be used under adult supervision at all times.