Korpa 
A clip on tuner that allows stress-free tuning.
The Korg AW-2 includes two clips (large and small) with a propriety design to accommodate a variety of concert band and orchestral instruments with different tuning "sweet spot" locations.
The Korg tuner's double ball-joint allows multi-angle positioning. An internal backlight lets you easily see the display, even on a dimly lit stage, and the backlight can be switched between Soft mode for low illumination and the high-brightness Auto mode, or turned off for well-lit situations. The energy-saving Auto mode automatically switches to the low-power Soft mode when no sound is present.
The AW-2 has a tuning range of A0 to C8. Special markings indicate pure major third and minor third intervals for authentic consonance. The Calibration function accommodates a variety of concert pitches. Users can select either the internal mic or the vibration-sensing piezo sensor for optimum response, which ensures stable tuning even in a noisy environment. The AW-2 tuner's Meter Reverse function allows tuning from any viewing angle. The tuner is powered by a widely available CR2032-type lithium battery (included), and with the backlight off, the battery life is an amazing 150 hours. Auto Power Off maximizes the battery life and a Memory Backup function is also included.