The bases are laser cut to ensure exact match up of hole sizes etc for mounting parts on your ATR or Vectoring Robot. The bases are made of 0.125" thick Aluminum for high strength, light weight, and it won't rust. You can also get them in 0.125" thick acrylic too so you can see through your robot. The bases can be stacked giving you lots of room for additional components. If you are going to load this robot up, the aluminum is stronger.
The bases are designed around the motor housings. The larger motor housing will only fit on the smaller rectangular base in the 45 degree position, if you plan to put the motors perpendicular (for standard straight driving) the larger motor housings will only fit the larger rectangular base.
900 MHz Rubber Duck Antenna - SMA Male Connector
900 MHz 3 dBi Rubber Duck Antenna - RP-SMA Plug Connector