This is a coaxial test cable with an SMA connector on one end and stripped center pin available at the other end.
The cable is flexible semirigid which has low loss, excellent shielding, is easily solderable and flexible.
It is very useful for testing RF circuits during development, allowing good signal and ground termination to points of interest.
It is also useful for making antenna feeds for circularly polarised antennas, (Skewplanar, Pin wheel etc).
To make a prototyping-grade RF VNA calibration kit you can create Open, Short and Match (50R) standards by yourself!
Open: Trim the coax wire length to around 1mm
Short: Solder a blob of solder covering the end of the cable, shorting shield to center
Match: Solder 2 x 100R 0402 resistors to the end of the cable between the center and shield.
This will give you an accurate reference plane at the end of these test cables allowing accurate impedance (magnitude and phase measurements) using cables already connected to your circuit under test.
It is not a $5000 calibration kit, but, will certainly give you accurate enough results for most matching and development needs.
Connection: SMA(F) / Stripped 5mm
Cable length: 63mm
Cable: Semirigid RG405 (0.085")