5.  AKA Carpenters Square  Used for measuring right angles  Most common use is for stairs and rafters

7.  AKA Speed Square  Commonly used for roofing, cabinets, door and window frames  Two inner scales are for establishing cutline's for rafters  3-4-5 triangle

9.  Most commonly used in wood working, masonry, and metal working  Used to check and layout right and 45 degree angles  Measures flatness

11.  Technical drawing instrument used by draftsmen  Made of aluminum  Used to cut and measure drywall

13.  Verifying elevations of foundations  Structural framework  Establishing proper drainage  Determining the correct elevation for floors  Establishing the height of doors and windows

14.  I-Beam Level  Box Beam Level  Torpedo Level

16.  Made out of aluminum  Are field serviceable  Used by contractors, drywall, ect  Magnetic pieces built into frame, usually have more significance in strength

18.  Solid pieces of acrylic that are machine set into the box level frame at a high degree of accuracy  Highest level of accuracy is 0.5mm in all level positions  More sturdy and rigid in its build

20.  AKA Boat Level  Used in small and tight spaces  Magnetic strip on bottom  Measures degrees and flatness

22.  Projects a straight line on a wall, floor or ceiling  Most commonly used for framing pictures  Used for measuring lines for painting