Where to find steel dome cones for speakers


Hi I have a pair of speakers that I would like install steel dome cones on the bottom so I can slide speakers around.  I'm not interested in flat sliders. I've searched partsexpress, audioadvisor, acousticsounds, eBay, Amazon etc without luck.  Any help would be appreciated.
dracule1
Looks like those are not the ones I recall want.  I've seen ones specifically for audio equipment that were half spheres and about 1.5 to 2 inches in diameter.
Looks like those are not the ones I recall want. I’ve seen ones specifically for audio equipment that were half spheres and about 1.5 to 2 inches in diameter.
http://magico.net/product/qpod.php
or
http://shop.mapleshadestore.com/Radiused-Footers/products/152/