The HORNBY X820 Cylinder Block is a sought-after accessory for model railway enthusiasts, specifically designed for the R859 Black 5 locomotive in 1:76 scale. Made of black plastic, this vintage piece is compatible with Hornby brand locomotives and is ideal for collectors looking to enhance their OO gauge model railway layout. Perfect for adding a touch of authenticity and detail to your train collection, this cylinder block is a must-have for Hornby fans and model railway enthusiasts alike.