It is a black nylon nut with a triangular head with a zinc-plated steel insert. These models are the same, the size of the fins different. The small nuance with the BPF 20 model is that there is a closed or open type which leaves some flexibility depending on your assembly.
The small wings of this wing nut allow a good grip.
These three nuts have the same shape of the head, the only element that differentiates them are its dimensions or its opening or non-opening characteristic so you can choose the part according to the dimensions of your assembly.
It is simple since, like all wing nuts, they are easy to handle and allow regular tightening and loosening.