These appear to be compilation movies from Gunbuster and Gunbuster 2. They are part of the Honneamise label which now falls under Bandai Entertainment as opposed to Bandai Visual (which folded up its US operation.)

Specifications are subject to change, but these are the preliminary contents:

Bonus Features:
8-page GUNBUSTER Booklet
8-page DIEBUSTER Booklet

On Bonus Disc:
Japan Premiere Report, Interviews: Gunbuster Re-Dub Session, Featurette: From Gunbuster 2 to The GATTAI!! Movie, GATTAI!! Movie Trailer

Specifications:
Disc 1: GUNBUSTER the Movie
Colour (Partly B/W) / Approx. 95 min. / Dolby True HD (5.1ch) & Linear PCM (Stereo) / AVC / BD50G / 4:3 (Partly 16:9)
1080p High-Def / Japanese Language Dialogue / English & French Subtitles

Disc 2: DIEBUSTER the Movie
Color / Approx. 95 min. / Dolby True HD (5.1ch) & Linear PCM (Stereo) / AVC / BD50G / 16:9 1080p High-Def / Japanese Language Dialogue / English & French Subtitles

Disc 3: Bonus Disc
Color / Approx. 90 min. / Linear PCM (2.0ch Stereo) / AVC / BD50G / 16:9 (Partly 4:3) 1080i High-Definition / Japanese
Language Dialogue / English & French Subtitles (Main Feature Only)

Discs 1 and 2 are available as separate releases, but this one gives you a bonus disc. However, it is the same price for the box set as the individual release, so you don't save any money.