There are a twelve of these that are slightly tarnished on the shells, other than that there is no difference to normal ones they just don't meet our normal standards so we want to clear these at a reduced price........ The tester is a 5-pin standard xlr and has three l.e.d.s displaying the varied faults and comes complete with a user guide. This is the tester that the professionals use to determine faults with dmx circuits. Works with any desk, dimmer or light that uses dmx including Avolites, high-end, martin, clay paky, coemar, vari*lite, pulsar to name but a few. Now comes with a lanyard to hang it round your neck or off a tool belt, printed ones are coming but for now plain ones will be supplied, there will be a new picture of these put up when the new ones arrive...