yeah, Ive taken them back to the shop and they are certain they are the correct belts and said there is only one listing for that model for belts. They are happy to give me a credit. I haven't had a chance to get an actual measurement around the pulleys on my mower yet, but will do so in order to determine exactly what size belts are needed to fit it. In the meantime I am wondering if maybe the pulleys have indeed been changed at some point in it's life...would you happen to have specs on the size pulleys that should be on the colt 5hp ??? Thanks again.