7mm APC7 adapters years ago were with common with rf and microwave test equipment, being one of the first precision rf connectors. It's a very precise sexless connector. Our SMA to 7mm adapters are good through 18ghz, the limit of our 7mm interface. We also offer 7mm to N adapters as well as 7mm to 3.5mm adapters. 7mm adapters are not as popular as they once were, but if you need a 7mm adapter we don't have, call, the designs are straightforward. 7mm to sma adapters are commonly used with older vna's. The 7mm to SMA female adapter is our most popular 7mm adapter.