O2COOL Deluxe Portable Personal Battery Operated Necklace Fans (4 Pack) This is for 1 of EACH color: 1 Blue, 1 Purple, 1 Pink and 1 Grey. Color coordinated break-away lanyard hangs around your neck for hands-free cooling. Compact design makes it easy for travel; easy to carry and store. Perfect for outdoor activities or indoors at a theatre, school or sporting events. Powerful one speed motor with internal 2.5 inch fan blade. Each fan requires 2 AA batteries (not included)