Just a larger version of the Render Buster. Well... not 'larger' just a bit shorter thicker in length from spine to edge and it has the kanji for 'heavy' written on it.

... I REALLY suck with Kanji.

I may do a side and over view image (like the ones i'll post soon) of this eventually to show the blades actual width. Its actually thicker than the normal Render Buster.