Vac-Alert Safety Vacuum Release System (VA-2000L, VA-1) features a non-electric, mechanical SVRS with a 0.170" orifice and 3.5 lb spring check valve, designed for suction lift applications to prevent entrapment in pools and spas. Constructed from PVC and 316 stainless steel, it reacts in under a second, ensuring safety with easy vertical installation.Compatible with suction lift systems (pump suction at/above pool water level); fits 1.5" PVC lines, adaptable to larger sizes, per Vac-Alert specs.Specs: 8" L x 8" W x 21" H; 0.170" orifice; 3.5 lb spring; meets ASME A112.19.17, IAPMO IGC 160-2002; 3-year warranty.Installation: Mounts vertically on suction line tee within 5 of pump; tools: PVC glue, screwdriver; 30-minute setup with included guide.Features: Fail-safe design prevents nuisance tripping; allows partial water flow up to 3.5 suction lift; no maintenance required.