Uxcell a14040400ux0543 4 Pcs 40 mm Diameter 12 mm Hole Diameter Threaded Round Ball Knob Handgrip (Pack of 4)<img src="http://ecx.images-amazon.com/images/I/41S-oMXm-6L.jpg" noproxy><img src="http://ecx.images-amazon.com/images/I/31IT4%2BI8%2B%2BL.jpg" noproxy>