These have been carefully removed from some surplus equipment.

The output is 15-0-15 so can either be used for analogue kit requring a split rail, or the centre tap can be left open if you require 30V at 0.5A.

The nominal 48V input will work between 18V and  72V.

The 'new' price for these is over £25, so these are a bargain at this price

They are intended for through-hole PCB mounting, but the pins are sufficiently strong that you can solder wires directly to them.