BeaterBlades will only work with KitchenAid Stand Mixers. There are 2 types of KitchenAid Stand Mixers and 3 Beater Blades to choose from.

If the head of your mixer tilts back, you have a "Tilt-Head" and need the BeaterBlade for Tilt Head Mixers. The BeaterBlade for Tilt Head Mixers will work with EVERY tilt-head mixer made, no matter the bowl size or power level.

If the bowl goes up and down, you have a "Bowl Lift". Now see if the lift handle has a rubber grip or just metal:
-If the lift handle is only metal, you probably have the 5-quart Bowl Lift and need the BeaterBlade for 5 Qt. Mixers.
-If the lift handle has a rubber grip, you have the 6-quart Bowl Lift and need the BeaterBlade for 6 Qt. Mixers.
-However, the 5 Plus model has a metal only lift handle but a 6 Quart Bowl. so you'll need the BeaterBlade for 6 Qt. Mixers.