I loved my ratchet rake.... until I bought a real tooth bar. Guess I should put my ratchet rake up for sale then, because there's no reason for me to put it on again (aside from making prettier, more uniform grooves in the dirt when raking, lol).
Is this for your B, or L3800 ? Like Josh says, just do a search, you could probably read for hours about them.
I've got both - and IMHO - they're for doing different things.
I got the Piranha toothbar because I was looking to do things like rip up sod and dig into dirt piles. It works well for that. I've been using it on a Kubota B3200. Prior to the B - I had a BX23 (smaller tractor) - and I had a "traditional" toothbar on that one.
Comparing the two - I think the Piranha is maybe a little less good at tearing into a pile of dirt than the traditional tootbar was - and it's not quite as useful for doing things like picking up rocks and getting them into the bucket as the traditional toothbar. What the piranha does well is dig into something and then leave a "smooth" surface where you dug. The traditional toothbar - because the teeth typically extend below the bottom surface of the bucket always leaves a dug up surface.
So I guess you could say each is for slightly different applications.
I also bought a ratchet rake in the spring - and I don't really see where that could be used as a "toothbar" per se. It's more for doing brush clearing where you have a bunch of stuff on the ground you want to "rake" up. I used it on my driveway to rip up the top few inches of compacted gravel/rock dust base - and then grade the whole thing out smooth and recompact it after it got all messed up over the winter.
But since the Ratchet Rake has teeth that point forwards and downwards - you're not going to be able to use it like a toothbar to assist in digging stuff up with the bucket.
I got a 72" ratchet rake just to clear out brush and small saplings that grew up after the loggers left a mess. I did try to do the driveway and made one pass on it and when the wife got home she said she could tell the difference. I already used it to clear me a area for a burn pile then took it off for now. My plans for my rake next year is to start making me food plots for my deer.