If so, there are several MFG's. But these just block the chute to control the discharge when required. Open 90% of the time, closed on demand the other 10%. So they are not for actual mulching if that is what you are wanting to do. You'll need to buy the mulching kit package from your mower MFG and mount it inside the deck.
What make mower do you have??? Make sure someone has put one on theirs first before you order. I've been told by almost all manufacturers that "theirs" will fit my GD Surfer but I've had to send them all back because they will not work.
My latest trial is the Trimmertrap version, we'll see if it works. By the way they said it would work as well. I havent heard anyone one hear say that they have an OCDC on a stander. Just my experience.
They are sending what would fit the old deck is my guess.
You may want to inquire with those you have already tried to see if they make a Gen II.
Maybe point out your deck is like then new 48/52/61 Chairot decks.