Our BOLT REDLITHIUM USB Cooling Fan provides powerful airflow up to 15 MPH and delivers up to 6 hours of run-time with the REDLITHIUM USB 3.0 Battery. It mounts securely on BOLT front and rear mounting slots and includes three air duct variations to customize airflow. The battery can be recharged in the fan via USB-C or swapped with an additional REDLITHIUM USB Battery. Compatible with all MILWAUKEE BOLT Safety Helmets and BOLT Hard Hats, allowing accessories to be secured simultaneously.