The Pomona Electronics Model 5748 - Maxi Universal Adapter Kit allows users to make their own adapters combinations, such as SMA to BNC or BNC to double banana plugs. Adapter’s ends are joined with coupling nuts. Simply choose your combination. All connectors feature
gold plated center contacts and silver plated bodies. 

Specifications:

Operating Temperature:
Items 1 through 9, and 12 through 20:
-67°F to +302°F (-55°C to +150°C)
Items 10 and 11:
+122°F (+50°C)
Nominal Impedance:
Items 1 through 9, and 12 through 20:50 Ohms
Items 18 and 19: 75 Ohms
VSWR:
Items 1 through 9: 1.2:1 (DC-1GHz)
Items 12 through 15: 1.2:1 (DC-300 MHz)
Frequency Range:
Items 1 through 9: DC-1GHz
Items 12 through 15: DC-500 MHz
Items 16 through 19: DC-300 MHz
Item 20: 50MHz -3GH