Why? Any boot-length shoelace will work, or cut yourself a piece of string.
You probably want a synthetic fiber (e.g. nylon) for water resistance (frozen laces are not much fun), and you probably want a round cross-section for better distribution of tension (when you pull on the ends, all parts of the boot tighten). In other words, a normal boot lace, or a normal piece of synthetic string.
String is one of the most-uses pieces of gear in my first-aid kit, and this is one of the most common uses. (In an emergency, if you don't have string, wrap the shoe in duct tape.)
It is not the length I am looking to get the specs on. It is the weight limit and material of the lace. Any string would not work but thanks for your response. It is odd that La Sportiva is not listing any spares or specs for laces. Duct tape is good
I had a lace pop on me just before a summit push, I pulled a lace from my trangos and used that , it worked fine,so maybe any boot lace, they used to sale replacements on their site but don't anymore, I did buy 2 laces from bentgate but they were almost to short, if they would have been an inch or so shorter I would not have been able to use them, I wear a size 44.