As you can see it does not fit perfectly and there is a small gap around the outside and the lens protrudes slightly further from the body of the phone.

Although the fit is not perfect, the camera takes the exact same quality photos because the light can pass through the glass lens exactly as it did with the original lens cover.

Because it protrudes further from the body, its prone to getting scratches.

I used this lens replacement for a month (before finding the HTC One lens assembly) and it stayed in place really well and did not fall out. As you can see in the bright close up image there are light scuffs on the lens cover.

If a protective case is used on the phone, then scuffing of the lens will not be a problem and this lens cover option will work just fine. Its just a little ugly is all.