Hits the triceps extremely hard.. It's very tough to unrack because it shifts around a bit. But that only makes you better.
Additionally, there's a lot more uses than a maximal effort too. Tons of variations.
Here's a few you can do that all result in different PR's to break.
Closegrip: 1 RM, 3 RM, chains, bands, combo
Medium: 1 RM, 3 RM, chains, bands, combo
Wide: 1 RM, 3 RM, chains, bands, combo
There's 15 different records to be made and broken.
As a supplemental, you're looking at triceps extensions and forearm work.