※The main unit is for display purposes only; the product is the case itself. We've created a case with perfectly sized inner compartments for both the receiver and transmitter, allowing for secure storage in the smallest possible size without any rattling. External dimensions are: Width 54mm x Depth 45mm x Height 93mm. While we're not sure if it was a perfect fit, we've received feedback that it could also be used for 20L (likely referring to a type of equipment). The lid snaps shut securely and is difficult to open unintentionally, but it opens with a simple press from the side. There's no chance of it opening and the contents falling out when turned upside down. Because of this, you can attach double-sided tape to the back of the lid and stick it directly onto an effects pedal case (＾＾). There's no corner interference during opening and closing, which is common with this type of product, allowing for very smooth operation. We had some concerns about leaving the unit directly on a surface during charging, so we've designed it to allow the charging plug to be inserted while the unit is still stored inside.