A flex hose is flexible and comfortable in use. A rubber hose is a little less flixible. The SPG without a hose either needs a hose, or, alternatively, can be mounted in the high pressure port of the 1st stage, directly.
The standard length of high pressure hose is approximately 80cm. A shorter hose of 56 cm, 20 cm or 15 cm, is often used with stage bottles.
These instruments (minimally) consist of an SPG
Suitable for use with Nitrox with an oxygen percentage higher than 40%
