This cap combines multiple technology and hides them underneath the cap . The bluetooth connection allows you to connect to your phone and music player which supporting bluetooth. Contain Micro SD Card input for both music playback and video record. Featuring private remote control to turn on and off for power and video recording, and there's also the volume adjustment. The cap design to cover the shine from your eyes while you jog, bike, or exercise in the outdoor . If you want to clean your cap , you can remove the screws and take the main unit and earphone out of the hat. There are Spy cam in front of the cap that you can record a airsoft game without holding a Camera DVR Specification: Video Format: AVI Music Format: Mp3 & WMA Memory Card: Micro-SD : 56MB/512MB/1GB/2GB/4GB /8GB Battery & Power Music Playing Time: 4 hours Video Record Time: 2 hours Battery: 3.7V 300mA Rechargeable Li-Polymer Nominal Charging Time: Within 4 hours Package include: 1x USB cable 1x earphone 1x charger 1x remote control 1x Operating Instructions CD Size : 220 × 310 × 120 mm Weight : 264g (Cap & Accessory )