[Yes] Most foot replacements use an external tightening/loosening knob. This foot uses an Allen wrench, and I am so thankful because foot replacements with a hand-turning knob always get in the way when carrying camera and tripod over my shoulder. Once a foot is mounted it will stay put and who needs a hand-turning knob. Love it -- nice and compact and functional. I use them on Sony 100-400 and 200-600.

[Aluminum] Replaces the original foot and offers a good fit and stability when fix on the gimbal or tripod.

[0.45 lb] Provides superior balance to factory foot while being arca mount ready - balance is great - good quality tool comes with it to insure easy and safe removal of screw bolts of original foot - I have the 400mm version of this product as well - delighted they made a 600mm version for the 600mm lens

[6 x 2 x 1"] Ideal replacement foot to allow easy mounting on your arca tripod head...robust.easy to install, compact ...a good item to buy for your 400 mm Sony 2.8 lens

[Aluminum] This addresses my only nit with the Sony 600mm f4: the factory foot requires a mounting plate. The Wimberley foot solves this problem and is a little lower profile to boot. Fit to the lens is perfect and the Arca profile is spot on. Highly recommended.

[Aluminum] I really like the Wimberley lens feet and use them on all my lenses. I ordered a RRS foot for this lens, but replaced it with the Wimberley, because I prefer the lower profile. I leave the feet attadhed permanently and, as opposed to the higher profile feet, they still fit in my lens bags and cases without having to remove them. The quality is, of course, excellent.

[0.45 lb] Wimberley has done it again! The Perfect replacement foot. My lens now fits better in my backpack and on my tripod. The lens is lighter and feels so secure! Please don't believe all that garbage that there isn't enough room to store the lens cap; it fits perfectly. I don't know why Sony didn't design their foot this way in the first place.

[0.45 lb] Easy to use and install

[Yes] If you use ARCA-Swiss compatible tripod gear, then a replacement foot is a no brainer. Surprisingly, as of late 2018, the usual suspects (Really Right Stuff, Kirk, a dozen Chinese companies) are still not out with their replacement versions, so this Wimberley AP-609 is the only product on the market. Fortunately, it is a good one, machined exceptionally well, to the usual Wimberley standards. Replacing the foot is a breeze, takes about 3-4 minutes. The foot comes with retainer screws that will prevent accidental sliding of the lens through your clamp on a tripod. They made the foot as long as they could physically make it - it gets to within about 1 mm of the hood, you cant make it any longer. It also protrudes about a1.5 cm towards the camera. That gives you enough length to slide the lens forward or backward on a gimbal to find the perfect balance with different camera bodies. Nothing more could be done! Reasonable price, too. Highly recommended.

[Yes] Brought this on a 6 day trip to FL and had no issues. Be careful not to overtighten the screws so you don't strip them. The included instructions tell you exactly how to tighten them with the included wrench.