This DCC Blanking plate will fit the standard 8 pin socket used in most locos. (OO, HO etc).
It comes pre-fitted with a 100uF25v Capacitor - giving you a stay alive capacity. This should allow a loco to cope with small, intermittent power interruptions from dirty track.
It also smooths out the peaks and troughs from a cheap train set transformer - meaning a modern motor will run with less noise.
Supplied in a heat sealed, anti static bag.