Bright-Way LED Clip-On Cap Light is perfect for baseball-style cap brims. It fits under brim and features two modes. LED Bulbs last over 100,000 hours and have 17 lumens of brightness. It is approximately 3.25" x 2" x 0.50" in size and comes packaged in a 6" x 4.25" blister pack. Uses two CR2023 batteries - included.