Review on Haoge LMR-SM140S Lens Collar Replacement Foot Tripod Mount Ring Stand Base for Sigma 100-400mm F5-6.3 DG DN OS Lens Sony E Mount Art 105mm F1.4 DG HSM with Built-in Arca-Swiss Style Quick Release Plate by Joe Roberts

Okay I've been installing this collar for about 2 months and it's essential for such a large lens. The fully extended lens looks like a modern-day rocket launcher. That being said, I recommend one of these if you're shooting with a tripod. This takes a lot of pressure off the eMount case. Now I wish Sigma would supply these via the manufacturer along with the lens, but it's relatively cheap compared to a proprietary lens. I honestly still think it cost a little more than it should have, but Sigma upped the price for third-party manufacturing. All in all, this is the nominal price you pay for camera body protection, lens protection and the ease of use of a tripod. I definitely recommend it if you have that 100-400mm lens. Time will tell as to durability, but feels like it's well made.