The MILWAUKEE® REDLITHIUM™ USB Bluetooth® Jobsite Ear Buds (2191-21) deliver UNCOMPROMISED SOUND, providing a powerful and balanced audio experience with the capability to take phone calls. Additionally, Jobsite Aware Mode provides situational awareness while reducing the intensity of loud external noises, allowing you to CONTROL YOUR AWARENESS. With up to 10 Hours of Runtime on a single charge, these ear buds deliver all day runtime. The REDLITHIUM™ USB case battery provides up to 70 hours of runtime using multiple in-case charges. Built to survive on the jobsite, this audio solution is water, dust, & impact resistant. Designed for on-the-job use, passive hearing protection is provided by silicone and foam ear tips. The Milwaukee® ear buds are kitted with multiple interchangeable ear tips and wings, for a secure fit. The REDLITHIUM™ USB Bluetooth® Jobsite Ear Buds deliver UNCOMPROMISED SOUND with the ability to CONTROL YOUR AWARENESS.