The Hornby R912 Power Unit is a 14.3V DC speed controller designed for model railways and trains. Made in the United Kingdom by the renowned brand Hornby, this pre-built unit is ready to go and suitable for analogue and DCC control systems. With a wattage of 250W and a scale of 1:76, this plastic speed controller is compatible with OO gauge model trains, making it a reliable and efficient choice for enthusiasts looking to power their railway collection.