These are Genuine Holley Performance Parts. Use This Spring Kit to Adjust The Vacuum Secondary Opening RPM. Sold as a 7 Piece Spring Kit.
Moroso for Vacuum Secondary Spring Kit - Holley - 7 Springs
HOLLEY 20-13 4150 4160 VACUUM SECONDARY ADJUSTMENT 7PC SPRING KIT
Holley Quick Fuel 38-1000QFT Quick Change Vacuum Secondary Diaphragm Spring Kit
Holley Quick Fuel Quick Change Vacuum Secondary Diaphragm & Spring Kit
Demon SECONDARY Bowl for Vacuum Secondary Carbs, Polished Aluminum
RPG Offroad 1.5" Level Kit Coil Spring Adjustment Collar 2017-20 Ford Raptor Blk