There are 55 front view textures and 55 side view textures. They can be combined to get a 3D effect (see the pics above).
Note: The textures are created in Photoshop with a size of 512x512. During export into PNG format the empty space was trimmed, so the textures have a non-power-of-2 format. The background of the textures is transparent.
The 'Other' file format you see in the product list on the top right is a Unity package, that provides the source textures and 55 prefabs to use in the Unity 3D game engine (see the pics with grey backround above, they're taken from the Unity engine).
The source PSD file contains all muzzle flashes, each one on a separate layer and organized into front + side view and the categories above.