Can't find out much detail but http://www.farnell.com/datasheets/1931349.pdf shows the Amphenol N series parts are rated to 11GHz. Maybe this termination is too - or maybe it is only 1GHz or so.
If you are looking for a low power N termination (at close enough to 50 ohms : 49.9 +/- 1%), $20 seems like a reasonable price.
Termination for a directional coupler up to microwave ??
Don't know how many they have available but be quick if you want one. Actually, 4 on hand at the moment pending orders in their system.
P.S. : Found on a different web site : Connector, coax. RF Terminators female N jack - 50 Ohm (49.9 Ohm). Frequency: 11GHz. Amphenol P/N: 82-5721-1000.