Lionel 2321-121 Horn Relay - Above you will find a single view picture of a Lionel 2321-121 Horn Relay as used in Lionel FM Trainmasters. Generally Lionel would change the part number from 2333-121 to 2328-121, 2329-121 or even 2321-121 after final assembly as these were pre-wired for the assembly line and some had different ground wire lengths. The horn relay shown consists of new old stock components, not some old junk taken from a junker engine, and we guarantee it to work as intended. In most cases we rebuild these relays as necessary. Although our new to like new original relays cost a bit more, this is a steal as it comes with a guarantee! There isn't any "as is where is" with these!