Which lens mounting has an arm that follows the upper posterior surface of the lens and usually has two screws through each lens?

The correct response relates to semi-rimless mounting, which is characterized by its unique design where an arm supports the upper part of the lens by following the upper posterior surface. This functionality allows for a more open design at the lower portion of the lens, which not only reduces the weight of the eyewear but also enhances the aesthetic appeal by limiting the presence of a full frame around the lens.

In semi-rimless montages, the lenses are often secured using two screws on each lens. This method provides stability and a secure hold while maintaining a minimalist look. This option is particularly popular among wearers who prefer a stylish appearance without compromising on lens support.

The other choices describe different mounting types with distinct characteristics. Rimless mounting typically lacks a full frame altogether, attaching lenses directly to the bridge and temples without a holding mechanism along the edges, while Numont mounting is a specific style of rimless that typically involves a single bridge with specialized hardware for attachment. Understanding these distinctions helps highlight why semi-rimless mounting stands out in this particular context.