The new GLX-D+ Dual Band Wireless Rack System features the premium MX153 Headworn Earset for high-quality vocal performance applications and the GLXD4R+ half-rack receiver. The perfect combination of the automatic frequency management with the new Dual Band Technology provides reliable and consistent performance while Shure proprietary Lithium-Ion rechargeable batteries provide up to 12 hours of use. Go wireless without complication.