rightey-o.
this thing probably at the way low end of knot count as listed.
this people sometime they count yarn ply as knots too --- remember. maybe someone should contact to clear up. it makes the tool look like a tool! lol
say the rug is actually 2 ply yarn 14 vertical and 14 horizontal knots an inch. Then someone comes along and does incorrect count of yarn ply going vertical at 28 instead of seeing it's a two ply yarn at only 14 knots. this makes the kpsi 392 (28x14) and then they think it's a single ply but only 196 if it's two ply.
so go like this with an appraisal The difference between a spinning a ply and making a knot can make big money difference. knots take time, a spin only needs a spindle