This is a lens holder for GoPro Hero4. Its useful if you use custom lenses with your GoPro. I helps keeping the lens in focus so you wont turn it accidentally. You will need one 3mm nut and bolt.
Also, you may want to help the nut with a soldering iron an to sand a little bit the flaps of the holder in order to make it fit perfectly.
Dont turn too hard as you risk to tilt your lens.
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