...They all have the same knot, so it's a case of what appeals at the time...
Perhaps @Electrif knows exactly what type of synthetic knots Zenith uses, but my TS506 is definitely not Plissoft. It has more backbone than Plissoft and it doesn't splay as easily. It's a great brush though and I would recommend it.It appears a Plissoft knot, true IYO?
I strongly suspect its Muhle fibre tied differentlyAfraid I don't know the type of knot, but as @FrankieG correctly said it is definitely not a Plissoft.