Daddario PW-CT-12 Micro Headstock Tuner

It's about the smallest clip tuner in existence, it's totally unobtrusive, you can stick it on the headstock and just leave it there forever. I'm using these on all my electric and acoustic guitars, also I've used it on my bass ukulele in the past.

The pros:
-small footprint
-quicker turn-on and turn-off time than the previous version, PW-CT-10
-quick response
- it's reasonably accurate for the practical purposes. My Korg CA-50 seems to be more precise.
- reliability. I've had two of the previous version for what, eight years now, and never had issues with them, if that's any indication.

The cons:
- tuning sensitivity. It sometimes struggles with the B string on a guitar, shows it as F#. And while it is possible to use this thing on a bass, you'd better use 12th fret harmonics to tune it. It doesn't pick the low B up on my five-string.
- viewing angles could be better. Sometimes the shape of the headstock prevents you from turning the screen directly at you, and it gets hard to see what's going on. The previous green version has better angles.
- it's a touch expensive for what it is.

Overall, it's a good, very small tuner. There are better options if the size isn't the primary concern.

Design:
The most eyecatching feature is its small and compact design. I do not like big ugly designs of tuners attached onto headstock, so i used a tuner pedal until i saw this tuner. That one is just hiding behind headstock and you cannot break it accidentally.

Screen:
It is really small but has a descent screen. I have been using it at home and i can say the brightness is very good. (What about using outside? Dont know honestly...)

Accuracy:
That clip tuner is not as sensitive and accurate as the tuner pedal i used. But its OK for such small and cheap solution.

Quality:
Clip is not strong. It seems as if it will be broken easily. I wish it was metal. But it is plastic unfortunately.

Closure:
When i saw this small design, i checked the price and ordered immediately. At the moment i am using it heapily, it is so handy and i eliminate one pedal from the pedalboard.

Surprisingly accurate even in moderately noisy environment and it's so small it's so convenient to take around and quickly tune or verify tuning.

Pros:
+Small size factor makes for low profile visibility and makes it convenient to take along
+Color display (angle of display can be rotated to adapt orientation of the device on the headstock)
+Works in moderately noisy environment (Instruments in the background, people chatting, etc.)
+Nitrocellulose lacquer friendly
+Chromatic tuner

Cons:
-Integrated metronome is limited to visual only

I've bought three of these by now. Very usable in home/studio environment. Easy and effortless to use, also light and doesn't take much space at all. I use these at home or just put one in a pocket of a guitar bag whenever taking a guitar with me. Good thing is the 007 factor of it - it's so small and well concealable - not making your guitar look like a tech centre nor your playing fussy.

Only downside of the tuner what I've encountered is that it won't be accurate/capable of measuring correctly in a loud and shaky (next to bass cabinet) environment such as rehearsal room while the rest of the band is making noise.

Very much usable in home environment and/or when playing alone/practicing. Very good and reliable product.