I recently bought one of these. At 1.2m x 0.5 m, it’s just the right size for a desk or small bench, and at $20 it’s a great deal! It has two snaps, so you can attach wriststraps or ground wires to either end.
http://www.newark.com/multicomp/082-0028f3/esd-bench-mat-500mmx1-2m-blue/dp/87P0236