Amphenol RF 242122 is a between-series coaxial adapter converting N plug (male) to BNC plug (male), 50 Ohm impedance, 4 GHz max frequency, straight body, gold plated center contacts.
Radiall R191417000 is a BNC male to N male straight coaxial adapter with 50 Ohm impedance and 4 GHz maximum frequency. It features brass body with nickel plating and gold-plated center contact.