Orico SSD optical bay adapter -OK for Mac Pro?

Does anyone know if the Orico dual SSD to 5.25" adapter will fit properly in the lower optical bay of a 2010 Mac Pro?
They're available at eBay for US$ 13.89 including international shipping.
The price is definitely right compared to OWC's 40 bucks adapter (+ shipping).

Didn't know about that 2.5" to 3.5" adapter sled. Might come in handy some day.

Are 5.25" drive bays standardized, meaning that the screw holes and any additional space below where DVD drives etc. are exactly the same in a Mac Pro as in any PC? If that's the case I see no reason to fork out the cash for OWC's rather costly adapters. I've just ordered mine via eBay and will see how that goes.

Edit: just found the silver colored Orico adapter for US$ 5.99 (+ shipping) at Amazon!

Re-edit: oh, I've found yet another one which makes even better use of the optical bay as it can hold up to 4 SSDs, or a combination of 3.5" hard drives and SSDs: Sharkoon BayExtension. I'm having difficulties finding places that sell them though, except for a handful German sites such as Mix computerversand for 5.19 Euros (plus shipping I guess).

I've received and installed the Orico dual SSD bracket which fits fine in my Mac Pro 5.1 (2010). All the screw holes lined up to the optical drive mount and the SSD fit nicely inside (one minor irritation however is that the Samsung 830 SSD was a couple of mm narower than the bracket, but inserting a couple of washers solved this -just beware that without the washers you tighten the screws so that the SSD will bend/break!).
I'll be buying another SSD soon which will go in the same bracket (there's room for two 2.5" devices).