Under the sprayhood, six of these cylindrical UMHW rollers help roll the halyards back to the cockpit. Sold as individual pieces, so if you need two enter a quantitiy of 2.
These measure 3/4 in. outside diameter, 3/8 in. inside diameter and 1-5/8 long.
Please check to make sure the part you're replacing looks like the one in the photo. There may be small differences due to manufacturer upgrades and redesigns.