Ice and Snow Studs
This model features the BUGrip technology in which the studs get pressed in when you are on a hard surface such as dry asphalt, but remain out to help traction when on snow or ice. They take pain to say that they don't guarantee you won't slip on any surface.
The BUGrip soles are not meant to be used indoors, as they can damage floors. This led to a bit of drama whenever I needed to wear them. How can I get out the door wearing them without having to sit down on a cold, wet step to put them on or risk damaging my floors or carpets? As opposed to wearing slip-on ice cleats, this also makes them less convenient as you would need other shoes at your destination. On the other hand, these won't slip off accidentally and are more suited to outdoor winter workouts.
The upper of the Kallax is insulated to -20C, yet the shoe is not heavy.
The soles of the Kallax are flexible in the right place for fitness walking, rather than being a stiff, inflexible boot.
The studs make your walking fairly noisy. I didn't like the feel of them on pavement, as I felt the studs were not needed and it felt odd to be walking on them.
Bottom line: These can be a great addition to your walking shoe wardrobe if you frequently encounter snow or ice. They are best suited for outdoor activity where you are assured of a change of shoes at your destination.