Can someone explain to me what 38507: RAIL ACCESSORY, NO. 4 (#6225519) is for? I've got this in the new Duplo Train accessory #10882 and can't figure out what it does :S


1 Answer 1


enter image description here It's an interactive piece that makes the train perform a cool(ish) function when it rolls over it.

enter image description here The train has a sensor on the bottom that reads the piece and does the deed.

enter image description here When the train reads this red one... it stops moving, which is sorta coolish for a jealous older sibling maybe ;).

enter image description here Watch 3 videos explaining all the cool possibilities. (1), (2), (3).

  • I guess only very new trains have this since my 10508 Deluxe Train Set V110 doesn't have the sensor. Does anyone know which train set has the sensor?
    – Nghia Hang
    Commented Aug 1, 2018 at 13:18
  • I personally don't own any DUPLO sets, so I'm just using the internet to do the friendly research. If we have a train set in question, double check with the box art. LEGO's box art calls these funky bricks "Action Bricks". If the box art doesn't promote the Action Brick and Interactive App feature, then it's most likely a no go. Commented Aug 1, 2018 at 16:35
  • 1
    The sensor equipped trains are sets 10874-1 and 10875-1. This group's common set series begin with "108", so it looks like any DUPLO train set that starts with 108 seems compatible, so far... Rest of the sets I see that have no Sensor Train,but the funky Action Bricks are 10872-1 and 10882-1.💪🏿 Commented Aug 1, 2018 at 16:57

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.