Hannabach 7004MT Durable D, 4th string Medium Tension

A: Hello Allan,
Hannabach uses a particular alloy to produce their durable strings. Here is the description from their product information listing;
"Durability, especially for the highly-stressed D4 string is made possible by using a very hard alloy which is also sweat resistant.

Our "Durable" blends in terms of quality and tension in the wide range of the Hannabach strings and can nicely be combined."

Cheers!