Injectory Assy for CSI Signature 3, or WaterSoft Isobar 3 softeners:

• #1--White Injector: 24,000 & 32,000 grain softeners
• #2--Blue Injector: 48,000 & 64,000 grain softeners
• #3--Yellow Injector: 96,000 & 128,000 grain softeners

If your injector assy has a check ball on it as shown, you must use this style of injector.  The Signature 2 / Isobar 2 style injector without the check ball will not work properly in newer systems.