This Aluminum Alloy Woodworking T Square Ruler Scriber is designed for hole marking, parallel scribe, and vertical scribe. It features a 45 Degree Angle Measurement, separable for use, and a drilling guide for mobile drilling and drawing. The scriber is calibratable for adjustments when needed. The package includes a Line Scribe T-type Ruler and a drill sleeve with 3mm, 4mm, 5mm, and 6mm sizes.