XL Systems N Scale Steam Sound Decoder W/ Speaker – For Athearn Challenger & Big Boy Only

This is a sound decoder with speaker, specifically for Athearn N scale Challenger and Big Boy.

Only those two—won't fit others without heavy mods.

Brand is XL Systems Inc.

Model type: sound decoder.

No MPN listed, no UPC.

Brand new, comes with speaker.

Drops in, gives you chuff, whistle, all that good stuff.

If you've got one of those big boys sitting silent, this is the fix.