Boker Cap Red Tree. The six embroidered ventilation holes ensure optimum air circulation just like the sewn-in sweatband with the three international Boker websites. Thanks to the practical Velcro on the back of the cap the width of the cap is variable. Specifications for Boker Cap: Manufacturer: Boker Age Group: Adults Color: Red Package Contents: Boker Cap Boker 09BO102: Cap Red Tree