Since DGT4000 is just a series number and not the model number we can't give you much guidance. We will need the numbers off of the model number tag that should be under the seat. Craftsman has been made by several companies and without that info we don't know what direction to send you.
Please in future quote the craftsman model number as Craftsman can be made by any mower company.
Yours is an AYP product
The deck bets are not standard sizes
The deck belt # 180808 is 21/32 x 89 1/4"
The PTO belt # 174368 is 21/32 x 90 3/8"
These are both kevlar fiber belts with cotton/kevlar covers.
If you are looking for cheaper belts then Oregon, Thermoid, Rotary & Stens all do exact copy 21/32" belts.
Most others will be the thinner 5/8" , B section belt which will need to be shorter to compensate for them sitting deeper in the pulleys.
