First impressions, I must say I got a little disappointed when I received these, because they came out of the little pouch leaking oil. But some paper towel will clean them up nice, but it would have been better if they came without having to wipe them for oil.
Overall they work great for their purpose, and don't let the price fool you, it's a great value.
I needed feeler gauges since I have a multiple of guitars that needs set up. This set comes super handy when you install a new nut and check the relief of a guitar.
The feeler gauges will help you to set up multiple guitars perfectly accurate, since you have a reference of measurements from one guitar to another guitar. This set has 32 blades that ranges from .0015" to .035" which is super nice for setting up string height at the nut and the neck relief.
I have used these feeler gauges to set the string height at the nut and the neck relief on a cheaper guitar, and with the setup the guitar is great to play on now after adjustment with these set.