These are builder tabs for people on a budget. These are puzzled into our sheets when making other products- so we can offer them at a lower cost. All Economy Builder Tabs are laser numbered to avoid confusion. Sold Individually.
Features:

• 2 1/8 Inch Long Overall when setting flat. (53.98 mm)
• 2.27 Inch width Overall (57.68 mm)
• 1/2 Inch Hole (.510 Inch actual, 12.95 mm)
• 3/16 Inch Thick (.175 Inch, 4.45 mm)
• For 3 Inch Tube (76.2 mm)
• Measurement from center of hole to radius is 1 Inch (25.4 mm)