1-Wire Earhook Earpiece Inline PTT for Vertex Standard EVX-S24 Two-Way Radios. Ear Hook 1 Wire: A straight through in-line PTT with PTT microphone. Industry leading 30lb pull strength at both ends of the PTT. Ear Bud rotates 360 degrees for improved fit. Ear Bud adjusts vertically for improved fit. Molded stress relief at connector. 36 Month Rapid Replacement Warranty.