It is a cheap and discontinued flashgun! The 56 model is also now discontinuedm, and unlike the 36, out of stock. The new 42 model is the only current model being shipped by Sony to stores, and the 58 is due in August. The 36 is a fair bargain.

The 56 is unusually versatile, and has functions which work (such as setting manual powers on the A350/200/300 when working in Aperture priority or Program mode) - the 42 locks out this function when mounted on these cameras, and we don't know whether the 58 will do so. If you can find a 56, get it.

David