These are official, authentic Husqvarna blades, so you know you are getting the best product quality with that famous Husqvarna reliability.
All Husqvarna Automowers are fitted with three blades, so the 9 pack would give you three sets and the 45 pack would give you 15 sets.
During normal use of an Automower the blades will lose their sharpness, and this will become more pronounced the larger your garden is. It is also worth considering that grass is usually damp with morning dew or overnight rain, and there is also an inherent moisture element with grass and clover. This moisture will eventually affect the blades.