This sturdy 3 leg aluminum frame allows you to use your Longacre Bubble Caster/Camber Gauge (Part No. LA78271) or Longacre AccuLevel Digital Caster/Camber Gauge (Part No. LA78291) to measure camber and caster on virtually any steel or alloy wheel from 12" to 17" diameter. Three-point contact to rim ensures accurate caster measurements. The frame even folds for easy, compact storage! Gauges are sold separately.