This SAE Recommended Practice shall cover mechanical- and electrical-readjust stroke indicators for air-brake actuators.This device shall indicate the foundation brake(s) may require adjustment or service when inspected per vehicle manufacturer's procedures. A measurement shall be made to determine actual stroke measurement for any system not factor calibrated.Stroke indication accuracy of an air-brake actuator can be assured only when all of its components are supplied by the original brake actuator manufacturer.This document establishes design guidelines for air-brake actuator stroke indicators.