It's the recently released DX 05 Zeon decal sheet from Bandai. This is the fifth in a series of special limited run decal sheets.
Bandai seems to have this love hate relationship with decals; a year or two ago they stopped producing water slide decal sets for their MG and HG lines. Many of the more sought after decal sets (Sinanju, Unicorn, etc) became scarce and prices began to skyrocket. Since then Bandai has started reprinting old decal sets, created the DX line of decals, included waterslide decals with certain ver. ka and limited edition kits but has not printed new decal sets.
The DX line of decals come packed in a protective resealable plastic sleeve. The decals come packed with a heavy cardboard backing to protect against bending and creasing. The decals are also protected by a sheet of wax paper.
The back of the package matches the Ace mark with the appropriate pilot or squadron. I recognize a few, Shin Matsunaga, Char Aznable, Ramba Ral, The Cyclopes team, Midnight Fenrir team; but I'm unfamiliar with the rest.
The set also includes some more 'interesting' markings like the Gouf and Zaku girls.
More Ace and unit icons.
The set also includes an abundance of warning labels, kill markings and arrows in different colors.
Unit numbers and affiliations.
Unfortunately it appears that this decal set is already out of production. If you can find a set and if you're a Zeon fanatic I would definitely encourage you to pick a set of your own up!
I have also purchased the DX 04 EFSF set, I will provide a first look at that set once it arrives in June!