What you have is a 252 , the differances are very easy to spot the 251 disk has a curved front main frame  &amp;  the clevis style hitch is ridged just like the 241 disk in Chris' picture. The 252 has a narrow streight front frame that the lift arm from the center tube on the axle is on the outside of the main frame &amp; the 252 has 4 gang angle holes to adjust gang angle. The 253 has a wide frame that the lift arm from the round center tube to the wheel hub assy. is on the inside of the main frame &amp; the 253 has only 3 gang holes to adjust angle.  Both the 252 &amp; the 253 have a hinged style clevis  hitch but  the 252 has a much shorter pole than the 253. They are all very well built disks but I think the 253 is a better fit if you have wings &amp; a larger HP tractor pulling it because the narrow frame on the 252 dosen't seem to suport the wings as well &amp; they tend to not turn &amp; plug or run in too deep. hope this helps