Peterson Tuners Pitch Grabber Mobile Active Clip-On Pickup for Use with Mobile Instrument Tuning Apps DESIGNED FOR MOBILE - Vibration pick-up plugs directly into mobile device INCREASE ACCURACY - Isolate your instrument from the rest of the room UNIVERSAL PERFORMANCE - Use with any mobile tuning app MULTI DEVICE - Compatible with iPhone, iPad, iPod Touch, Android phones and tablets EASY PLACEMENT - Wide, padded jaws safely clamp to any instrument