Very rare in Alpa mount, portrait lens made by Schacht.

Schacht lenses were mainly made in Exacta mount. This particular lens type is usually known as TRAVENAR

For Alpa, it is mounted in an EXTENSAN tube.

This lens and the rest of the Schacht family is discussed in detail in :

Marc James Small, NON-LEITZ LEICA THREAD-MOUNT LENSES, A 39mm DIVERSITY, published by Rita Wittig and available, signed and with addenda and corrigenda, from the author for $45 postpaid in the US. Marc msmall@roanoke.infi.net FAX: +540/343-7315