These are three-foot N to N jumper cables.  We make them with Amphenol connectors and Belden 8214/RG-8A/U or 9251/RG-8A/U high quality 50-ohm cable.  The connectors are not crimped on, but rather they are soldered on.  This dramatically increases the reliability because they stand up to more physical abuse and are water tight.    The cables are rated for DC through 1 GHz and are custom made in any quantity desired.  Three-foot cables are $38.00 each.  Add or subtract $1.16/ft for cables other than that length.

Using Times Microwave LMR-400DB cable, the three-foot cable is $39.00.  Add or subtract $1.48/ft for cables other than that length.  The DB suffix indicates it is rated for direct burial.  LMR-400DB is good from DC to 5 GHz.