This is the SimpleOSD Ultralight Edition from Flytron.com. It weighs about 3 grams and is roughly the same size as an SD memory card.
The OSD came nicely packaged in an anti-ESD bag (a sign of a serious manufacturer). The total package size was tiny, which makes the shipping cheap. The OSD does not come with any physical manual, but you are directed to an online manual. The manual is very clear and full of pictures and diagrams, which explains everything in detail.
The PCB is made from a thin glass fiber lamination making this OSD super light weight. I work in the electronics manufacturing business so I couldn’t help admiring the layout design of the tiny PCB. This designer knows his stuff