There are various terms for helmets that are molded in one single operation where the outer shell is bonded to the expanding foam. Some are copyrighted phrases. We long used "molded in the shell," a generic term. Others use terms like in-mold or in-molded, and Bell has a copyright on the term co-molded.

This can be a superior technique for making helmets. It permits larger vents, a mixed blessing. It is also known as co-molding or molded in the shell.

The Kask Rapido Road Cycling helmet is made with a polycarbonate shell using ‘in-mold’ technology to join the outer shell with the inner EPS (expanded polystyrene) liner for better shock absorption and a lighter frame. Twenty four air vents provide a cool air-flow on the hottest of days.

The most durable road helmets have a protective polycarbonate shell that extends down around the base of the foam liner, leaving very little of the liner exposed. Helmets with this type of full-wrap shell tend to get banged up less during everyday use. However, many helmet manufacturers choose weight savings over enhanced shell coverage.