Poorly designed plates. I work in a learning environment and often have problems with tablets. When looking for a plate for your BM camera, keep the following in mind: 1. You want the aperture rods to be able to go through the plate, not the plate they end in. With this plate you need to buy and replace different length rods if you have different length lenses, otherwise the turntable on the matte box will hit the rods and you won't be able to use the polarizer. Mechanism. Many students tend to accidentally unscrew the entire mechanism, which then falls out and parts are lost. The worst thing is that the plates and threads are aluminum, which means that over time the plates will wear down to the point where they are exposed and the bars can no longer be blocked. Inserting a helical coil to solve the problem is difficult due to the design of the disk. 3. You need a strong tripod connection. The entire V-Lock system wears out over time and does not provide a reliable connection. The film industry has used baseboards for many years, which are fast, reliable and easy to use. This is a TV dish that will not stand up to prolonged use/abuse. Find yourself a dovetail and base plate and you'll be much happier, plus you can use them for different cameras too. You need a very long Allen key. I recommend applying thread lock to the screws. I think there are better aftermarket pens for these cameras although I haven't used them. I hope this helps you make a better purchasing decision!