Step 2 mailbox 5411

A specific address!

According to the USPS, a Step 2 mailbox with the address 5411 is a mailbox located at:

5411 Step 2 Mailbox [City, State, ZIP]

Please note that the city and state are not provided in the address, so I couldn't look up the exact location. If you're trying to find the location of this mailbox, you may want to contact the USPS or check their website for more information.