- What are the dimensions of this item? What is the maximum embroidery size it can do?

total dimension-5 1/2" x 2 1/2" (regular size socks), embroidery area-appproximately 2 x 2; 3" x 1 1/2" (baby socks), embroidery area approximately-3/4" x 1 3/4". I love this item.

Will this work with a ricoma hoop?

Hoop sticky backing, sticky side up. Place the loaded-sockeasy on the sticky backing so it sticks, load your hoop and embroider away. Commercial hoops are commercial hoops -- Ricoma's are no different with the sockeasy. A hoop is a hoop, is a hoop. Again, load sticky backing onto the hoop, not the sockeasy. FYI: I use a 6" round Tajima hoop for 1 item. I use a 10" square Tajima hoop for 2 or more items. What size hoop depends on how many items I need to stick on the hoop.

Are these the ones by Cookie???

Yes they are , they are fabulous and very easy to use.

Does this work on gloves/mittens?

I think you could, especially the smaller mittens for babies. That's a great idea. Embroider the hat/mittens/scarves sets for children. Yes, I think it will work.