The Niscomed B.P. Armlet Long Tube is to be used with the sphygmomanometer. When measuring blood pressure it is important that the posture of the upper arm and lower arm is correct in order to get the right reading. The long tube facilitates this as this is what connects the machine and the armlet. This helps to measure the pressure as this is what blows the air into the cuffs and releases it later so that the pressure is measured.