TAPaulk's Elite Series listen only earpiece offers a discrete listening environment for those needing the best made gear at a price they can afford. For use on TAPaulk's or other brands speaker mics and two-way radios. Comparable to much higher brand models, the TAPaulk™ JH-003-D is a great choice for any user! Product Specs Top grade materials used in manufacture Rugged Kevlar™ coiled PU cable 2.5mm plug 40 inch coiled cord Field replaceable parts Adjustable D shaped earpiece Speaker Specs Speaker size: 15mm Impedance:32ohm Frenquency response: 20-20KHz Sensitivity: 84db.