The TY-LP75 is thinner than the standard plates supplied with Sirui heads. But she has no rubber pads and must be strictly tightened with the enclosed Allen. After that, they will not budge. Even without a condom it leaves no traces of paint, which was important to me.
Well, I think that the front plate has rounded edges so they can be easily inserted into the Arca shot of head. Due to their thinness, they can remain permanently mounted easily and hardly disturbs. Even with the plate fits 300/4 L IS still well in the standard quiver.
For larger telephoto lenses my full recommendation to buy, 5 stars.