The 12 Hole Spark Plug Tray was designed to be compact, light, and durable while maintaining all the features that mechanics want. All the holes are marked for cylinder number and location (Top & Bottom). With the handle extended it is 4 3/4" overall height and when the handle is down, it is 2 15/16 " overall height, allowing it to fit in most toolboxes. The replaceable rubber feet allow it to sit securely wherever it is placed. There is also room on top for customized lettering to personalize it or add a company name.