This compact 4 1/2 in. finish square is ideal for access in tight quarters for finish carpentry, setting saw blades and more. CNC machined from extruded aluminum and finished with the same glare-resistant EZ-Read anodizing process that made our Johnny Square famous, this laser-etched square is durable enough to withstand any jobsite abuse, and is backed by Johnson's best-in-class limited lifetime warranty. This rafter square also features continuous scribing notches that are ideal for ripping lumber from 1-1/2 in. to 3-1/2 in. as well as handy markers that measure 2x4 board dimensions of 1-1/2 in. and 3-1/2 in..