Simple installation - I used some 3M Red body panel tape to stick it below my head-set. It is in view while riding - but doesn't clutter the dash area. I routed the wire through the head-set opening next to the tach, down through and under the battery area to the spark plug lead, where I wrapped it several times and covered it with a cable cover.
Tach comes with a 6' sensing wire....but maybe do not cut it - use the extra length when wrapping around the spark plug/coil wire to get better readings?
Not sure how long the battery lasts - but mine has been on there for 535 hours of riding.
It will hold your top RPM's after a ride ("where was it when climbing that big hill at near WOT?")......and I like to take a look every now and then to see what the engine is turning at as I cruise country roads, or check your idle speed.
This is the one I used - there are plenty of others.
https://www.trailtech.net/ttoStig