Here’s a YouTube video review, TASCAM TC-S1 Solar Tuner. A great, lightweight yet sturdy, and compact tuner that charges an internal battery by solar power. Small enough to fit anywhere. Features 4 tuning modes: Animated Strobe, Meter, Needle, and a Fine Tuning mode as well as calibration from A437-A445. A fast internal processor coupled with a responsive onboard mic or 1/4″ phono jack for input. A mini USB connection for charging and an included silicone sleeve for protection.
Check out the video for operating instructions and a demo if the features.