I have an answer for you. I reached out to my tech at Swagman, and she confirmed that the replacement key with code 1231 is for the cable lock on your Titan 2 # S63400. Unfortunately, she also confirmed that the only way to get additional/replacement keys is to purchase a new cable lock. We do not currently sell the cable lock for the Titan 2 individually from the locking hitch pin. For that replacement, that is the Anti-Rattle Hitch Lock and Cable for Swagman Bike Racks w/ 1-1/4" & Combo... view full answer...