kitchen drawer slide

[jwruta]

One of our kitchen drawer slides on our Rockwood Mini Lite 2109s broke so we need to replace it. I don't know if the length is determined when the slide is closed or fully extended. I'm hoping to be able to match it to the existing one so I don't have to replace both of them. Where's the best place to purchase a matching one?
Thanks for the help in advance.

[bob caldwell]

Measure closed.....Lowe's or HD have singles, but you need to post a pic of the one you've got