see the clamp it specifications  
Clamp-It Assembly Square Features of the Clamp-It
ASSEMBLE PERFECT 90 DEGREE CORNERS

  • Use it as a third hand to assemble any two pieces at 90° or even to put a cabinet together one corner at a time
  • Attach it to a work surface and it becomes a right angle fixture for bench assembly
  • High-impact, rigid polycarbonate ensures strength and accuracy
5" CLAMP-IT™ BAR CLAMP
  • Throat depth is 3/4" to clamp center on the assembly square, and the length of the bar is 5" to clamp any wood thickness up to 2-1/2"
  • Sold in pairs.
SKU# 10-031 $155.99*, 10-032 $43.99* --*Check the Where to Buy Section for prices from your preferred retailer  
in use images of the Clamp-It in use images of the Clamp-It
in use images of the Clamp-It in use images of the Clamp-It