15 is the series. I have the 2516 which is the 16 series. I stole this off the net.
00 series - Dependable, tough, heavy duty utility tractors with modern styling & additional features for greater operational versatility. Available in both 2WD and 4WD models.
10 series - Heavy duty, versatile compact 4WD tractors are equipped with many standard features.
15 series - Time tested, economy series of 4WD compact tractors for light to medium duty applications. Models available in standard gear or hydrostatic transmissions.
20 series - Versatile, heavy duty, full platform utility tractors loaded with an extensive list of standard features.
25 series - Economy price rugged utility tractors that offer versatility and ergonomic comfort.
30 series - Versatile and rugged utility tractors designed for ease of operation & loaded with a big list of standard features.
C series - Rugged, heavy duty tractors with contemporary styling. These 2WD compact utility tractors are best-in-class in weight, lift capacity and front end loader lift capacity.
CAB series - Heavy duty and versatile compact 4WD cab tractors with an extensive list of standard features.
And the ML is the loader type.
