The Holga 12MFC Flash is compatible with Holga cameras and any camera with a hotshoe and has a guide number of 39' at ISO 100. It features a ready light and test button, and can be recycled in just 6-8 seconds. This manual flash operates on a single AA battery and includes red, blue, green, yellow, and diffusion filters for added versatility. It is designed to fit on a hot shoe and can be used with the Holga 120N, Holga 135, and other cameras with a hot shoe.