The RSA-3408-1 adapter is designed for optimal performance in the 0 to 6 GHz frequency range and bridges the SMA and MMCX interfaces. The MMCX interface is becoming more popular in applications where very small size with multi-GHz performance is critical. It features a gold-plated machined brass body, gold contacts and PTFE insulation. The knurled band on the body provides enhanced gripping for installation of the adapter. Price is $5.89 each.