IMO, Kevlar caused my TE - which took a few years to completely heal. I will NEVER use that stuff again. It's akin to using guitar string. Kevlar does NOT maintain tension as it has very little elasticity. When stringing Kevlar on a D/W machine, it stretches ZERO - unlike poly which stretches a fair amount, depending on the string. There is a reason few use Kevlar - even pros. It is a soft tissue killer. Avoid it.