Look into the basket under the spiders and look at the coil. If the coil is flatwound (smooth, wires look flat) then its a level 5 flat wound coil. If the wires look round its a 4 layer level 4 coil. Lastly, the stiff spiders on the fives look "rough" while the level 4 soft spiders are smooth. I would explain the different dust caps but you can't tell unless you take it apart ha ha ha