Micron Magic Bags with Micro Particle Arrest One 9 pack for 9 bags total Genuine Product OEM 197394.  This is the twist and lock type system. 

Fits the following Kirby Vacuum models:

• Diamond Edition 
• Ultimate G 
• Generation 6 or G6 
• Generation 5 or G5 
• Generation 4 or G4 
• Generation 3 or G3
• Heritage II