For the record the Gates belt for the stock pulley on the SRT6 is K081145.
The 06 and the 08 numbers in the part number tells how many ribs are on the belt.
The next four numbers are the outside belt length in inches.
Line the ribs up correctly to the pulleys with ribs or your new belt will be soon ruined.
Some makers just use a part number that do not indicate the belt sizes.
There are charts on the internet that give the correct part number for interchangeable belts.