The filter fits nicely in the air box. Though it differs significantly from the old filter, it does its job of keeping snow out of the carbs if snow should come thru the large air vents in the shroud and land on the air box. You don't want the carbs sucking snow into them, I suggest that DK mention the difference in shape and size rather that state that it is an exact replacement. .
This foam is for the exterior of the air box, goes between the air box inlet and the vent hole on the bottom side of the hood. It is not recommended to use this internally, could cause performance problems.