I have a Canon 70D with an 18-35mm ART from Signa attached, a very massive and heavy lens and this ball head takes it without issue. Based on this, I can take 99% of camera / lens configurations of enthusiast photographers!

K&F Concept Square Metal 100mm Filter Holder with 8 Lens Filter Adapter Rings 49mm to 82mm. Great addition to my filter collection. I bought the wrong size filters so I had to buy this kit. Well built product with most of the adapters I needed. K&F seems to be making some really good stuff at a great price that will help us amateur snappers without breaking the bank.

In addition to square filters, I also bought the low-cost magnetic filter holder set. I can only say top. However, I lack the possibility of obtaining ND 8 and ND 64 (magnetic) because only ND 1000 and polarization filters are available. A second glass-filled filter holder is included, which is super durable with adapter ring for a second lens size and yet! fits into the super handy case. For the time being, this low-priced set with magnetic holder is enough for me; for further demands, I will probably switch to another manufacturer's “large” filter holder system (about 400 euros with three ND filters). Which photographer doesn't know this “want to have?” In short: Riko Best's contribution to YT convinced me. Would I recommend it? Yes, anyone who wants to work with grey filters now and then. LG

Among several domestic and foreign companies offering square filters, I decided on this one because it is easy to put on and take off from the lens, it is thin in the front and back, and it comes with a C-PL filter
For C-PL filters, just open the lid and drop in from above. If you make a mistake in front and back, it will not fit.
The square filter has just the right amount of friction and doesn't feel like it's going to fall off.
Almost all metal, except for the four metal adapter rings and C-PL filter, the holder alone weighs 110g.
In terms of design, the overall impression is sophisticated.

up until now, square filter holders from other companies have been expensive, and we have endured with SIOTI holders.
I also had an old K&F holder, but it is difficult to use C-PL.
That's where this product comes in. I bought a set of holder + C-PL + ND1000 for the time being, but it is well thought out. There is no vignetting even at 16mm with the Nikkor16-35mmF4, and there is no annoying color cast.
I'm a little worried about the C-PL's adjustment dial squeaking, but I have no complaints at this price with this content.
After that, I would like to see a frame that can be attached to the existing filters sold on the overseas official site, and a filter case that can hold about 6 to 8 filters with the frame attached.
~Addition~
I purchased a 100x150 frame from the US site of K&F. Existing filters can now be used, and full-scale operation is now possible.

My stepfather gave me a Nikkor f1.2 50mm! To adapt it to my Canon 70D I had to get a ring... it's really nickel, I don't regret the purchase! No games and no snagging — it's easy to put on and take off! I recommend buying this item with your eyes closed.

Good value for money!

In addition to square filters, I have now also bought the cheap magnetic filter holder set. I can only say: great. A second glass-filled filter holder is included, which can be held up permanently with an adapter ring for a second lens size and still! In short: the article convinced me. would i recommend it Yes, everyone who wants to work with a neutral density filter from time to time.