lens spanner wrench

I am looking around for a lens spanner wrench. I was wondering what people are using out there and what they would recommend.
thanks
Roger

I've been using both of these. The first is more useful for
big optics, the second one is better for smaller stuff.
I still sometimes need to make my own though; seems
nothing handles all possible sizes.

http://www.edmundindustrialoptics.com/onlinecatalog/displayproduct.cfm?productID=1457

http://www.edmundindustrialoptics.com/onlinecatalog/DisplayProduct.cfm?productid=1745

Another option:
http://www.skgrimes.com/span/index.htm

Larry

My home brew version which I used to loosen a too tight objective ring was clamping a stainless steel office ruler in a Workmate with just enough sticking up to engage the ring. I used a bargain basement rubber strap wrench from a bin in an ACE hardware to turn the tube. Worked beautifully - no chance to scratch anything or cause any damage with my particular assembly. Might work for somebody else. Since only the edge of the thin SS rule is sticking up it is well supported and even with quite a bit of pressure it didn't bend it. That objective lense was tight !! The bit of astigmatism in that scope went away after loosening this.