just шнурки (but not шнуроки)

sounds in Russian words fall out when stress shifts just like in Hebrew, i.e. gader - gderot, seder - sdarim

so шнурок is singular but шнурки/шнурков etc. is plural, and for that matter in all nouns with suffix -ок

at the same time this rule may not be applicable to some words with -ок being a part of the stem as in порок (vice), сток (drain), наскок (a pounce), прок (use)

прок and сток could be simple to figure out cause after reduction you'd be left with no vowels which militates against pronunciation, therefore it's retained, but not the other two

there're words with -ок seemingly belonging to a stem, which in fact are derivatives of other words formed through the suffix -ок, and therefore they follow the rule of vowel reduction, like мешок (a sack) which is a derivative of мех (a skin in a sense of a container)


here's a thread you may find useful in shoelaces respect

"Tie your shoe and zip your pants!" (and related expressions)


Quote Originally Posted by Valda View Post
"шнуроки для ботиноки"
шнурки для ботинок

ботинок is another word following the described rule of disappearing vowel, so in plural it'd be ботинки, in singular declined - ботинка/ботинку/на ботинке