This item was created out of a perceived need for Mercari users. We are confident you will be satisfied with this product. This is a tool to check if items can be posted via Yu-Packet Post, made from cypress wood. It has 4cm and 1cm slits. The material is cypress. Cypress has a pleasant aroma and is soothing. The wood is flexible and strong, becoming more polished with use, and is kind to nature. And the texture of the wood is superb. It is unpainted. The material is cypress wood approximately 14-18mm thick. It does not bend like a thin ruler. It is sturdy, like an actual postal slot. You can check in advance whether your package can be crushed and inserted. We believe there are no commercially available measurement tools with this thickness. The photos are for size and shape reference. The item you receive will be of equivalent quality. If you would like measurement slits of other thicknesses (e.g., 1cm or 5cm), please contact us via the comments section on our custom order page. While it may take some time, we will do our best to accommodate your requests. We will use recycled packaging materials. If you purchase multiple items and they can be shipped together, we will reduce the price, at least by the shipping cost. We may change between Yu-Yu Mercari便 and Raku-Raku Mercari便 without prior notice. Thank you for your understanding. #TakawataHandmade #TakawataPackingScale #YuPacketPost4cm #YuPacketPost #ThicknessMeasuringRuler #ThicknessGauge #ThicknessMeasuringItem #ThicknessMeasuringGoods Yu-Packet Post Thickness Gauge 4cm