Prime-Line Products M 6003 Tub Enclosure Flat Roller， 7/8-Inch，(Pack of 2)<div style="text-align: left;"><strong>[Product Information]</strong><br><ul><li>Two No. 8-32 x 3/8" Phillips binder head machine screws</li><li>Threaded hex hub</li><li>Made in China</li><li>Threaded hex hub</li><li>7/8in. nylon ball bearing flat wheel</li><li>(2) wheels with screws</li><li>Fits most J shaped tracks 7/8 in. tall</li></ul></div><img src="http://ecx.images-amazon.com/images/I/41xVJkPhGpL.jpg" noproxy><img src="http://ecx.images-amazon.com/images/I/41PhrekQCjL.jpg" noproxy>