This specialized thru-hull fitting is designed to enable a 3/4" thru-hull passage thru a transom or livewell wall and to attach an aerator screen on the other side. This fitting allows the screen to mount flush against the wall with no extra nut to secure the fitting. Perfect for remote mounted pumps for filling from the transom or for recirculating from the livewell. The T-H Marine AS-1 strainer fits this part.