Missing cat

Orange Tabby Cat. Male. He has a Bobtail (a very short tail). He is wearing a dark colored collar that is super thin and has a small bell on it. His name is Sigfried or Siggy for short. The cat is very sweet just skiddish. He usually will sit next to the door if he knows we are leaving. My husband was running late for work and the cat snuck past him and ran out. Unfortunately my husband was not able to catch him. Anything will help!