Fits Kirby Generation 5, Generation 6, Ultimate G, Diamond Edition, Sentria models. Kirby magnetic vacuum roller. Replaces Kirby brush rollers: 152505G, 152505, 152599, 152597. How to use the belt lifter on Kirby G3, G4, G5, G6, G7, Ultimate, Diamond and Sentria vacuums. The following video shows how to use the strap adjuster on your Kirby Sentria upright vacuum cleaner. Vacuum. This also applies to older Kirby models such as G3, G5 G Six etc. How to adjust the brush roll on the Kirby Upright Vacuum. The following video shows how to change the roller brush on Kirby vacuum cleaners.