1-Wire Earhook Earpiece Inline PTT for Vertex Standard VX eVerge EVX (See List). Compatible with Vertex Standard VX10, VX130, VX160, VX180, VX210, VX210A, VX230, VX231, VX261, VX264, VX300,  VX350, VX351, VX354, VX400, VX410, VX420, VX451, VX454, VX459, BC95 eVerge - eVX-261, eVX531, eVX534, and eVX539 Handheld Two-Way Walkie 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.