Whistle, Train 4.5V, Adjustable with Yellow Base

Reference

upn0312bc01

BrickLink® #

x870bc01

Whistle, Train 4.5V, Adjustable with Yellow Base (part upn0312bc01) is a LEGO element. CollectORbuild's catalog records it in 2 sets, including Electronic Control Unit (Forward/Backward - Stop) and Electronic Train.