The 173-5 performance has been computer optimized to meet your application. Physical construction emphasizes long term electrical and mechanical durability. Elements are rod 3/16” 6061-T6 aluminum, grounded to the boom. The driven element “T” Match uses a CNC machined central block with O-ring sealed connectors. Internal connections are encapsulated in a silicone gel with a dielectric strength 3.7 times greater than air for enhanced power handling. Balun connectors are triple O-ring sealed to the coax.