You are looking at an OO Gauge Twin Stonework Railway Train Tunnel Track Double Portal Entrance
Portal dimensions are added as an extra image but basic dimensions in text format below, keep in mind when looking at the image there are 2 of these in this set and the dimensions do not include the side wall sections.
Each portal size: 12.58cm W x 0.77cm D x 11.6cm H
Edge caps/middle joining piece: 1.9cm W x 1.0cm D x 12.5cm H
Total width when set up as per image 1: 27.5cm
Please Note: These items are 3d printed, far more sturdy than plaster or laser cut cardboard models, all items come unpainted in grey.