Bought two of these to be able to tune two tension rods simultaneously on opposite sides of the head. On one of the keys, the red plastic part is not solid, so it starts to slip when you start getting some resistance. In other words, I cannot use the two keys to achieve the same level of 'finger tight' by holding on to the red plastic part.
Otherwise; it's a drum key. The red plastic is a good idea for the finger tightening (if it was always solid, some quality control might help with that) and the red color makes it easier to find when you inevitably drop it, especially in dark gig conditions.