I have a Bell Pis Boss. It has an adjustable inner strap and a removable neck curtain that covers ears and a drop down sun shield. Works pretty good in spring, summer and autumn. It is more of a Polo style than half helmet.
Bell Pit Boss Helmet Reviews - RevZilla
The Bell Pit Boss Helmet has your perfect fit on Speed Dial. Get low-profile DOT protection with a removable neck curtain and drop down sun shield.