The Niscomed B.P. Rubber Bulb with Valve Imported is a rubber valve with a bulb which is used in sphygmomanometer. This has to be connected to the tube and helps to get reading on the scale or the dial, whatever is being used. The valve has to be used to tighten and the pressure can be measured with the bulb. Both of them are made of high quality material which makes sure they are good and give correct reading.