Two plate primary dob mirror?

I noticed an ad on AM from yesterday showing a mirror for sale that is 'superior' to single plate mirrors.

Gimmickry or ??
To me it looks kind of silly. Is this anything new?

http://www.astromart.com/viewad.asp?cid=216470

This looks like a Stabilite mirror. You can check them out at http://www.stabilite.com. I have an 18" mirror from them, although mine is the radial design (look at the pictures of various blanks on their website - mine looks like the 30" pictured). It does work well, is lighter, cools down fast and stays at ambient. I added a fan to mine tht blows into the space between the plates for even faster cooldown. Also, you can put the mirror retention clips over the back plate so nothing is in front of the mirror. The downside is that they are harder to figure - mine was done by Zambuto, but he apparently only made 1 or 2 before deciding they took too much extra effort to figure properly for him to make money on them. The one in the picture looks like a blank (uncoated and unpolished) - not clear if that is a picture of the actual one being sold (since the ad lists a Strehl ratio....).

Hope this helps,

Jarad

Hi Mark,

I actually have one of these mirrors, 11". It is physically made well, but I have not had a chance to look through it yet !!!!

Anybody else have one?

David Simons