The Klein Tools' Lightweight Cooling Fan Is Designed to Fit Klein Tools Hard Hats (Cap Style and Full Brim) and Klein Safety Helmets to Primarily Direct Airflow to The Neck Area and Back Of The Head. The Quiet Fan Can Be Independently Controlled, Adjusted and Positioned For All Day Comfort. The Compact Fan Attaches to The Side Accessory Slots to Maintain Good Balance, Low Profile, and Help Focus Airflow. They Can Be Conveniently Flipped Up For Storage When Not In Use. Powered By Klein'S Modular Rechargeabl