The best chromatic tuner I've seen.

Those clever guys at Guitar Tech have come up with a brilliant chromatic tuner which could have been designed for hurdy-gurdy. No unnecessary buttons - just on/off. The display is a big graphic of the note and a useful virtual needle to show deviation. The whole package is so small that it clips nicely to the trompette ear so can be left unobtrusively in place. It seems to sense all strings right down to the low d drone . As well as using the clip as normal, it's possible to cut off the  clip from the body and then you can use "Blu Tack" to attach it semi - permanently to the keybox side. The redundant spring clip works great as a mute for the chanterelles. You can get one on line for 14.99 + p&p or from me at a bargain 11 inc. uk postage.