Measuring 280 by 220-200mm this mat provides plentiful recreational area for your mouse but certainly isn't too large, think 30cm ruler by 2/3's of one if you're trying to size it in your head:
Like the Icemat, the Corepad is made from glass, this gives the mat a nice weight and the pattern branded into its top should be very hardwearing, an issue with some plastic mats:
The bulk of the pattern atop this mat is a lattice of small holes in a grey background ('fencing'), these give optical mice something to track with and I'm happy to say the mat performed very well with my IntelliMouse Explorer 3, I didn't experience any jitter (whereas on sheet glass the mouse doesn't function at all).
A combination of weight and four small rubber feet hold this mat firmly in place:
The only downside to its glass construction is the thickness required to ensure strength, 5mm in this case...
...this means that when using this mat without a wrist rest it'll be elevated a few mm further from your desk then with a thin mat, which isn't ideal from an RSI point of view.