There are several styles. The early ones take two countersunk (flat head) screws and have a smaller backing washer. It has just the two sides bent up to form the sides to fit over the flat part of the clip stand. These are shown on the timbales.
The next version was the same size but was bent to provide a channel to allow normal screws and for the spring clip. The picture included shows the later style with the channel. The older ones would have been flat across as the yellow line indicates. Most of the newer ones had the spring clip. These used two screws for the bracket top and bottom and two on the sides as shown on the red white and blue kit shown.
The later ones had a larger washer and had four holes in the bracket. Two in the same spots as the old style brackets and two more. The backing washer was larger in diameter and had four holes top and bottom and two on the sides.
Since the earlier style didn't have the extra bends for the spring channel, the clip of the stand is closer to the shell.
They will all still fit on any stand but the early ones will be too close together for the big felt ring on the later stands.
Versions two and three are shown below.