OK, the '2"' number is not useful for this product. It appears to be the "maximum hole size" that this product is good for in direct drilling (which it does not do). When I worked it with a 1" bull-point sharp-nose, it cut very well, but I could see how a 2" point might be its practical limit. This of course depends on how tough your rock is, and also the chisel shape. I am sure it will drive a 4" broad narrow cutting edge as for pavement trimming.
The shank measures some over 0.7", so is probably 18mm. (SDS is a German design so would be metric.) Nevermind that, you want "SDS Max" shank. (Not "SDS" which is a smaller size.) The working end should be less than 2" round or maybe 4" wide flat-bit. Try this link: http://www.homedepot.com/s/sd%20max%20chisel