i hate to start an argument........but. The current chains from agco are 557 chain. that is as heavy a chain as can be run. the manchester chains may be heavy but the material is less than what i would call great, they wear with the older 550 chains. as for the wonderful feeding of that manchester......sounds good on paper.....not so good in all conditions in the field.that little extension that is supposed to accelerate material at back of chain also keeps material from entering very well.i have installed several agco 557 chains latley and they have come down in price and in the case of r40-r52, they have been less than aftermarket. just my thoughts......