In series 2.4mm adapters to 50 GHz and 1.8mm up to 67 Ghz.
For frequencies up to 27 GHz, the 3.5mm interface is popular for test benches. P1dB has 3.5mm to SMA adapters operating to 27 GHz with a max VSWR of 1.20.
P1dB's high frequency terminations include 2.4mm, 2.92mm and 1.8mm.
Attenuators with 2.92mm, 2.4mm or 1.8mm interface are in stock.