Bb horn with A/stop valve and additional F natural valve
The model W 125 has in addition to the A/stop valve an extra quart valve / F valve.
Until the end of the 80s many of these horns were used by high horn players in symphonic orchestras. This models aren`t just instruments for students at all. They meet the highest standards in sound and playability.
The conical measure was continuously improved and corresponds on the current state of knowledge. You can compare the sound of the W 125 with the Bb part of current double horns. With the additional F valve you can play nearly the same range as you can play with a double horn.