01Laser source make and serial
Four of the six listings we checked offered several interchangeable source makes at the same headline power. The source is most of the value and most of the warranty risk. Get make, model, rated power and serial number on the pro forma invoice.
02Welding head and wobble
The head decides how wide a gap you can bridge and how tired the operator gets. Compare wobble width, protective lens type and price, nozzles supplied, cable length and gun weight.
03Wire feeder
Four listings included one, one excluded it. Without filler wire you cannot fill a real fit-up gap. Ask for single or double wire and the diameters it takes.
04Chiller or air cooling
Two listings offered an air-cooled version beside the chilled one. Ask the rated ambient range and what happens when coolant runs warm in summer: derate, alarm or stop.
05Safety interlocks
A handheld unit should fire only when the nozzle touches the grounded workpiece. Check for that clamp interlock, a key switch, an emergency stop, and eyewear marked to EN 207 for the wavelength.
06The 3-in-1 promise
Cutting and cleaning nozzles are priced in whether you use them or not, and cleaning at welding power is weaker than a dedicated cleaner. Price the welder alone first.
07Whose warranty
Four listings stated two years, two stated one. Ask whether the source maker or only the seller covers the source, and who pays freight on a failed one.