I have that same brand, but a larger size, and it worked great. I had it in an outdoor coop for 10 chicks I got awhile back. The weather was quite chilly outside, but the babies were nice and toasty !
I only used it for about 2 weeks, as the chicks were 3 weeks when I got them. the legs are independently adjustable, so I set it up with the front higher than the rear, so it was sloped so they had varying heights to snuggle against.
I got it used from a friend who used it to brood a mess (20) of Guineas, and they were impressed with it's function.