Poulan Oil Seal part# 019051 supersedes to part# 530-019051. This oil seal has an outside diameter of 1-3/16" and an inside diameter of 9/16". Following is a list of chainsaw models that use this seal; S25AV, S25DA, and S25. There may be models that use this part that we do not have listed here. Please refer to your owners manual or a parts breakdown for your model, to assure that this is the correct part for your machine, before you order.