"What am I missing here?"What am I missing here? The plastic bag from the Echo 361 chain says "91VXL053XJ".
Could both the Echo and the Makita chains be LP but since the Makita is .043 the teeth also has an even more narrow profile than what it would be on a .050 chain?
Low profile is a trade marked term belonging to Oregon. Notice how that Husqvarna package says 3/8mini. reduced also has been used
91VXL Oregon product 9=small class of 3/8 pitch chain 1=0.050 drive link thickness
90px Oregon product 9=small class of 3/8 pitch chain 0=0.043 drive link thickness
Oregon also uses a lettering system for the pre packaged stuff at hardware stores around here and omits these numbers.
Stihl
63pm3 6=small class of 3/8 pitch chain 3=1.3mm drive link thickness=0.050
61pmm3 6=small class of 3/8 pitch chain 1= 1.1mm drive link thickness=0.043
Carlton and some newer names may have the same size cutters for both drive link thicknesses.
Stihl 61pmm3 is better than similar class 0.043 chain. Opinion
We are clogging up the test thread