Interdynamics LDS-1 3 Ounce IA/C Stop Leak & Detector Pinpoints and seals common R-134a A/C leaks in O-rings, gaskets and seals Red dye detects major defects requiring mechanical repair Formulated for all R-134a car A/C systems For use with all standard R-134a gauge and hoses Requires adaptor for use with self-sealing valve R-134a gauges and hoses (DVA-1 sold separately)