Pro Series Exercise Ball Slow Deflate Yellow 45cm. Stockings Quantifies specific dB and frequency 16 7136 Quantifies specific dB and frequency hearing loss with precision testing * Offers a full range of frequencies and intensity levels * Frequency modulated stimulus mode for reliable results with children and elderly patients * core strengthening and stability Excellent Retail Packaging * This ball was specially designed to deflate slowly if punctured thereby reducing risk of injury * Provides improved stability at the points of body contact and enhanced performance due to the responsive surface design * Comfortable to sit on * Great grip thanks to built in latitudinal ridges and an outstanding texture that doesn t feel like plastic * Comes with two plugs an inflation adapter a measuring tape to help insure proper inflation and a poster detailing 24 exercises