Shockproof.Latex-Free.Exclusive Pressure-Distribution System.Pressure-Proof Manometer. Ensures durability and reliability.Micro-Filter. Protects valve and manometer.Large-diameter Scale. 56mm diameter black-on-white scale is easy to read.High Quality Indicator. Precisely calibrated, durable and shock resistant.Large Insufflation Bulb. 50% larger bulb Volume for fast inflation of the cuff.Exclusive Air-Release Valve. Provides fine and precise air release rate adjustment, quick deflation, and extreme durability. A rubber-stop prevents valve-lock.