The Veritas Dual Marking Gauge is a neat and easy to set up marking gauge.  Use to mark up both of the lines in one go for the groove inside shrink pots.

This is what Canadian makers Veritas say:

• Accurate, premium quality marking gauge
• Ideal for laying out mortise and tenon joints
• x2 hardened steel wheel cutters
• Cuts wood fibres, rather than tears
• Marks cleanly, even on cross grain
• Wheels retract into the head of the gauge for storage and protection
• Can be used as a single-cutter making gauge
• Very easy to set up

The aluminium housing has a brass face and the rods are stainless steel.

Due to their small size it would be difficult to sharpen the cutting wheels on the Veritas Dual Marking Gauge, however they can be replaced if damaged.