2tall

Hello all, I have a very stiff link on my chain, I can work it free but seems to be stiff when I ride the bike the next day, and makes a noise going over the front sprocket. (I'm guessing it’s this that’s causing the noise). Is this due to a missing O-ring or is there anything I can do to free it up totally? Also what damage am I doing by riding it (80 miles a day) with a stiff link? Cheers,,