These are Grado's latest Limited Edition headphones. Open back design with dynamic drivers, an 8 conductor cable that is terminated with a 3.5mm mini plug and includes a 1/4" adapter. The Hempwood housing has a maple inner sleeve, an adjustable leather headband and replaceable Grado F cushions. Throughout the development process we learned about all the uses for Hempwood and when we were done we realized there was a new use, creating a incredible sounding headphone. Full bodied bass, detailed mid-range and lively highs is what you will get from these beautiful headphones. Each pair hand-assembled in Brooklyn, NY, USA.