You are looking at an OO Gauge Single Stonework Railway Train Tunnel Track Single 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 the dimensions do not include the side wall sections.
Portal size: 12.58cm W x 0.77cm D x 11.6cm H
Edge caps joining piece: 1.9cm W x 1.0cm D x 12.5cm H
Total width when set up as per image 1: 15cm
Please Note: These items are 3d printed, far more sturdy than plaster or laser cut cardboard models, all items come unpainted in grey.