It seems like a quality product. If you haven't purchased something similar before, it might be a bit challenging for you. You can find a relevant video on YouTube.
It doesn't open in the middle. Open the lid, apply pressure with a screwdriver at the point where the cable will pass through to release the contents. After connecting the cables, reposition it from the correct side.

Very good quality. It is not all made of rubber. It also has some hard plastic parts. The connection is made by opening the plug from the top (drawer-style) and not on both sides.

For its price, it's impeccable. Waterproof and sturdy. The spring on the cover ensures its waterproofness. Although it doesn't come with instructions, with a little relevant experience, you can easily find the way to connect it. The only negative aspect is that it's a bit bulky. I highly recommend it.