When you change the Len for your camera, if the angle is too wide (the len with too much curve), the result might not be good for all cameras. So it is better for you to buy only 1pc to test the result first before buying in batch.
No refund / exchange if the combination of this Len + your camera cannot achieve good result.
This new 2.1mm Len is used by HS1177 Camera (sold by us), the quality is better than normal 2.1mm Len.
Note: This camera is being sold as 170° Go Pro camera Len by some other dishonest sellers at higher price but in fact it is only 140°. Please becareful.
Important: The camera Len cover is not included for 2.1mm curve Len (the good one).