Oh. Looks like the key you get with a 345 or the like. My manual (lc9s pro) says use a paper clip. I thought that was cheesy on Ruger but so far it just falls out. May start to bind a bit after dirty or more use.
Ruger sells these too.
http://shopruger.com/Internal-Lock-Key-Assembly-LC9-Mark-III-P345/productinfo/62089/