What is Valles and why is there a Hechsher of Eida HaCharedis?

Valles is a name brand in Israel of Tzitzis wool that sells for more money. Their strings are supposedly much thicker and they supposedly do various Hiddurim that regular Tzitzis don’t have, hence the hechsher. The dye though with Valles is sourced by both R’ Yechezkel Toporovich’s Chabura and Ptil.