SR1552 MRSLOTCAR Foam Tire Inserts For 16.5 - 17.3mm Air System Wheels.
Package contains six (6) foam donuts/inserts.
Tip: Use as many foam donuts as necessary (typically 2-3 per wheel) to fill up the entire width of the gap between the two wheel flanges. Once in place, carefully sand the foam so it stands slightly (.010" to .020") proud of the wheel ribs. Then mount your tire.