The Shadow SH P3B Professional Preamp is made for slim body and round back guitars. The volume control has an extra large knob. It comes with endpin output-connector.
The SH 099 Under Saddle Piezo Pickup fits classical and acoustic steel string guitars with a standard bridge slot width of 2.3mm. (3/32") Pickup installs under the original saddle and is only 1.8mm thick.