K&K pickup and mic systems can be used on a host of other instruments. Some of the more popular ones are listed here.
Tenor guitars are growing in popularity. The usual option is the 2-head Twin Spot bridgeplate transducer, although other hybrid pickup/mic systems can be supplied if preferred.
For cittern or bouzouki type instruments I usually recommend the Twin Spot for smaller-bodied instruments and the Pure Archtop for larger/deeper/archtop instruments. If you prefer an externally mounted system for a floating bridge type folk instrument then the Definity or Definity Pro is the way to go.
Piano and accordion systems are also listed here. The piano system was developed in cooperation with the renowned German piano manufacturer Seiler Pianos. The accordion system provides one of the best ways of ensuring a good balance between treble and bass.
There are two violin systems. The Violinissimo uses a tailpiece-mounted jack socket, whilst the Violinissmo Pro uses a side-mounted carpenter jack system.
For wind instruments, there is the CXM5 Saxophone Microphone System, and the Silver Bullet mic system for clarinet, flute or trumpet - available with either a jack or XLR preamp. The Hot Harmonica is a great option for both blues harps and chromatic/slide harmonicas.
Some of these systems are special order from K&K in Oregon - allow 15-20 working days for delivery.
Also see multi-use systems listings.