Brand: SmartRacing Products
The square-section Holder Leg is the vertical piece that holds one end of the String Bar in the Smart Strings 4-Wheel Toe Alignment Kit (formerly Pegasus Part No. 3180). The string bar fits into a tube on this leg and his held firmly with a set screw. The other end of the bar rests on the Hook Leg. The Holder Leg is Item 3 in the SmartStrings instruction sheet.
These legs can get tweaked bouncing around in the trailer. If the leg is not straight you will have a hard time repeating your set-up.
Sold individually, one required for each end of the car.