Fan belts, Air condionining belts and power steering belts.
V BELTS ONLY.
There are two main types of belts
15 *** 15=11mm or .44 top width
EXAMPLE 15350 BELT IS 15= .44 350= 35' LONG OR 11MM X890 MM
17 *** 17=13MM or .53 top width
EXAMPLE 17350 BELT IS 17= .53 350 35'LONG OR 13MM X 890 MM
Most belts go up or down in half inch stages
So 15 350 15 355 15 400 15 450 ect ect
15 belts are usually for water pump and alternator/ Power steering belts
17 belts are usually for power steering and air-conditioning
Obviously the wider the belt the more it sits up in the V
