Audsley describes this stop as follows: The name that has been used by certain German organ-builders to designate an open bass stop simply in contradistinction to the covered stop Gedectkbass. It is an open appellation, conveying no idea of pitch or tonality. Williams states that the name �could apply to Prinzipal pipes in the pedal ... but was usually an open wood stop�. Wedgwood considers it a synonym for Major Bass.
Osiris contains six examples at 16', nine at 8', and one at 4', all in Pedal divisions. The oldest known example is given below.