GMAX GM55 Solid Half Helmet XX-Large | Off-White The GM55 half helmet has a retractable sun shield with a lightweight, small shell design that sits down on your head. GMAX's innovative classic design with cutting edge features is a true winner with the cruisers!Features. Retractable hard coated sun shield, changeable, simple no springs design. Premium venting reduces heat at the top of the head. Comfort liner, shell and styro designed for maximum venting without reducing the integrity of the helmet.