There does seem to be an awful lot of confusion on whether these links are "one time use only" or reuseable...

I was looking for a link to allow me to quickly remove my Shimano 10 speed ultra narrow (5.88mm) chain for cleaning.

The KMC web site shows this link http://www.kmcchain.com.tw/index.php...o=view&id=1051
which is for a Reusable MissingLink 1/2" × 11/128.

I could never find the CL559S link in the US, and would up buying 2 from England...I assume the CL559S stand for Chain Link, 5.59mm, Shimano...

FWIW....

DPN