valve on/off?

[skyless]

How do i tell the difference between on/offs. I have several and they all look different. How do it tell the difference between a RT, classic, standard xvalve, I have a ult and i know that one. One i have has is brass with a square top, another is round. Thanks

[Coralis]

classic valve on/off top (note this is latest version of the on/off top the older version was a round disk with a + etched in the top


Rt/xvalve on/off

[skyless]

Awsome thanks, The rt and the xvalve are the same?