Recharge, Relax, Repeat. [Crystal Clear] DX400 is designed to focus on the human voice. [Recharge] This quick charge solution provides up to 36 hours of use (3 days). [Removal Batteries] The low-cost, detachable battery modules provide reliable power for years to come. [Easy to Use] DX400 rechargeable comes with a dual-port magnetic charging set, multiple tubes, variety ear dome packs, and cleaning kit. Simple rechargeability, simple adjustment.