Milwaukee BOLT Safety Helmet Cooling Liner is designed to keep you cool and comfortable on the jobsite. Activated simply by running or submerging it under water for 30 seconds, this cooling liner uses advanced microfiber technology to absorb moisture and heat, providing up to 4 hours of cooling relief. Its soft, comfortable padding ensures long-lasting comfort while being fully compatible with MILWAUKEE® Safety Helmets. Part of the BOLT™ Accessory System, it also allows users to secure multiple accessories simultaneously, making it a versatile and practical addition to your safety gear. Model Number: 48-73-4544