The heads swap either way on the tool and the iyp365 I like the smooth heads better on the tool which I use much more often then I use the iyp. I like a bunch of people am sad that they went 219C vs the 219B. IMHO it's a neat little trick to get a better low mode and makes the Nichia Tool a more useful light .I've edc'd a Tool like this on and off for that past few years.Super light weight ,good feel in the hand,firm snappy clicky . You get used to the M/L/H driver the more you use it and it's obviously much better in a clicky vs a twisty light