Funny thing in the world of rat traps. You know the old saying, build a better mouse trap and the world will beat a path to your door .... it's weird, but the Victor model that I think is best is not sold in most hardware stores. I get a box of 10 or 12 from Amazon for around $30.
My crudely drawn arrow points to a small rectangular open box of sorts, you can put the peanut butter-bacon fat mix in that, won't roll off as it will somewhat when put on flat part. I put a little on the flat part as well, my thought is more surface area = more scent. I've seen people put a nice tidy arrow on photos, I use Paint, they don't have an arrow you can drag and drop on your photo.
These are less prone to that lousy but common finding: the bait is gone but the trap unsprung. This compared to standard, older design with the small rectangular bit of metal with the little piece raised up to grab the hold down rod by the side. The platform is larger. They will tend to put one leg on it while reaching for the food. Better leverage for tripping the trap
There is nothing to catch on the yellow plastic thing, just the friction of the rod being pressed against the underside of the yellow plastic. I suspect they're referred to as the professional model because it's easier to nab your finger than with the standard model. Takes a bit or practice. They also have a smaller mouse trap model with the same design. The other brands aren't as good IMO.