Our built-in comb is designed to evenly separate lashes, creating a perfect curl, unlike traditional curlers which can cause eyelashes to overlap and twist in different directions. All metal parts are made of carbon steel (a stronger and stronger metal than stainless steel). The spring hinge helps to adjust the correct amount of pressure applied to the lashes. The built-in comb is designed to touch only the lashes, (never the eyes) adding additional support to the lashes as they curl, creating a correct shape compared to a sharply bent shape. Ergonomic design (fishing handle) makes it easier on hands and fingers. The charming secret of eyes of all shapes and sizes, both Asian and American. More Curl!