I have these in all my stalls right now, but they’ve started falling apart less than a year into having them. The blocks also fall out of them once the horses lick them down a bit.
I’ve thought about just hanging an additional water bucket and putting the block in those, but I have at least one horse who loves to fling buckets off their hooks just for fun, and those flat back buckets are like $20+ each now.
Not a fan of 50 lb blocks on stall floors… they get covered in pee and shavings too quickly.