Workman - CB Rubber Duck Antenna Workman CB Rubber Duck Antenna is designed for reliable CB radio performance with a tunable tip for precise frequency adjustments. It features a 5/16" threaded base, making it easy to mount on most CB radio setups. Covering a frequency range of 26.965 to 27.405 MHz, model KR1WP ensures clear and consistent signal transmission. Tunable Tip 5/16" Threaded Base Freq Range 26.965-27.405 KR1WP Still looking for the perfect part? Having trouble finding it? Call our product experts at 603-224-7370 and let us lend a hand. EXTRAS Extras The following products are meant to be used or paired with the product above. Workman - 2510 Power Cord Workman - HD Dual Fused Power Cord Workman - Power Cord Still looking for the perfect part? Having trouble finding it? Call our product experts at 603-224-7370 and let us lend a hand.