This swivel piece locks the ball into place. The knob fits my thumb, so tightening it is easy. It locks really well and can turn to hold my camera longways, sideways, or leaning.

The ball head and monopod are a good light weight combination for travel or hiking with a backpack. Works great for my zeiss binocular mount. Excellent for my htc vive lighthouses. You just have to unscrew the smaller one to reveal the bigger hole tha...  Read More

The tightening knob is too big. If you tilt the top far enough, it's not possible to tighten and untighten it.