What is rf connector, Ultra-Small Coaxial Connector, coax connectors tool,

 U.FL Series 6 GHz 50 Ohm Receptacle Male Pin Ultra-Small SMT Coaxial Connector

https://www.futureelectronics.com/p/interconnect--connectors-rf--bnc-connectors/u-fl-r-smt-1-80-hirose-electric-5053722