iShoot Lens Collar Tripod Mount Ring B(W) Compatible with Canon EF 70-200mm f/2.8L USM/is USM/is II USM/III USM, EF 100-400mm f/4.5-5.6L is USM, EF 35-350mm f/3.5-5.6L USM, EF 300mm f/4L is USM

It worked well...a perfect fit. I just used it for an outdoor project in 50mph winds and it held up flawlessly

This sturdy collar fits the lens well, and has a 1/4" thread to match my Manfrotto QR2 quick release plate (sold separately elsewhere). It also has an alignment hole adjacent to the threads, This is seen in the seller's photo of the bottom of the plate, to the right of the arrow. The hole matches up with a similar hole in the QR2. The QR2 kit includes a plastic antirotation pin that goes into both holes, preventing the lens mount from rotating with respect to the QR2 plate. Manfrotto says this pin is for camcorders, but it also works with the IShoot B(W).

Can’t really give a review. I sent it back …ordered the wrong size. Wouldn’t fit camera.

This ring allows smooth and precise rotation of the lens and has a one piece solid thread mount--unlike the canon OEM ring which has a sleeve threaded insert that is prone to snapping.

I found the grey cannon 100-400mm like 90% off only because it was missing the tripod mount. This simple and appropriately priced product was wellllll worth the price to complete the lense.It's of quality metal and weight. Fits perfectly. Balances perfectly once on the lense. And is easily removed if you want it out of the way to go hand held if need be.

Exactly as expected. Fits and solidly built.

I purchased this tripod mounting ring for a Sigma 105mm f/2.8 Macro Lens which has a 78mm barrel and it works beautifully!

This is nicely made and sturdy. It fits over the screws within a small channel in the ring. Couldn't be happier to find this! Shipment was quick too!