This is a new Universal Joint to replace MTD part numbers 631-0045, 731-1731, 731-1730, 731-1729, 751172 and 699010.

This also replaces Atlas part number 751172 and 699010.

The larger hole fits a .625" shaft and the smaller hole fits a .403" shaft.

This fits a variety of snowblowers including the following model numbers:

Atlas A520N
Atlas A520ESN
Atlas HM520N
Atlas HM520ESN

Please let us know if you have any further questions on this item!