The R191970091 from Radiall USA, Inc. is a 50 Ω coaxial adapter from an SMA jack (female socket) with SMA 2.9 female to an SMA jack (female socket) with SMA 2.4 female.
The R191977020 from Radiall USA, Inc. is a straight coaxial adapter with an SMA plug (male pin) at one end and an RP-MCX plug (female socket) at the other, 50 Ω impedance.