The Oakley DRT3 Trail adult bike helmet is a feature-rich mountain bike helmet for exploring new terrains. Its approach to design reflects a distinctive style while improvements to fit and function that make this helmet suited to take your ride to the next level. It features the Oakley BOA® 360 micro-adjustable fit system designed to optimize the fit experience of the rider. This system is both height adjustable and features a micro-adjustment dial on the back of the helmet for a customized fit every cyclist will appreciate.