But I'll ask again, are you using the foam inserts that were included to adjust the fit for the lenses? Yes, without using any of those the rings probably wouldn't fit properly on a lens. But using them I've been able to fit the rings on all my lenses, just have to adjust which pieces of foam to use.

But I basically just use three lenses, so I've got three rings adjusted to those and don't mess with changing the foam around.

All the rings come with foam. On one lens, with the foam is just a little bit too loose. I tied the lens with rubber bands so it gets better contact and friction. On another lens, I have to remove the foam to fit. Then the magnet only locked tight on one end. So to me, it not a perfect design. The gear from Jag35 use screws. they are perfect fit.

Not to beat a dead horse, but just so anyone that reads this is clear about how the rings work. The rings do come with foam already on them, but they also come with a pack of additional different sized foam so that you can swap them out for a perfect for for your lenses.

I've only used them on three lenses but after working out which foam to use with which gear , they've worked great.

I'll second that statement re: customer service. I asked them about additional parts for my indifocus and stopped trying after several emails went un-answered. I was going to order a dslr rig, but decided to build my own.

Their products are well made and the prices are competetive, but after purchase support sux. The Indian retailers on ebay always respond to my emails (ironic).

Sadly in my experience the Indian products are utter junk whereas with all the stuff that I have ordered from China (batteries, lighting equipment etc) I have been pleasantly surprised with how really good the quality is.