[time-nuts] Identifying Picosecond Pulse Labs Part?

[AC0XU (Jim)]

I have acquire some Picosecond Pulse Lab parts, about 2 in long with SMAs at either end. They were advertized as DC block/2 GHz low pass filter. 

However
a) It isn't a DC block - DC resistance from input to output is < 1 ohm.
b) It isn't a low pass filter - S12 is quite flat at 0 dB from 0 to 20 GHz.

Also, DC resistance from input or output to ground is infinite.

The only identification on it is "Picosecond Pulse Labs 9008". Any thoughts as to what these things are?

Thanks!
Jim