I am a carpenter. commercial construction every day. I have had this laser for several years and use it constantly. They do a lot of acoustic work and use it to mark walls and ceilings. Ideal for leveling partitions, check with tape and always level. Used for installing metal frame walls. It is designed to be installed over the bottom rail leg with the line on the laser side. You can easily install the top rail with the bottom rail already installed. Ideal for mesh ceilings, can use square lines for layout, and the mounting bracket is designed to be mounted on a wall corner at wall corner level, no line binding and easier than large rotary lasers. It is possible to move the laser along the arm to align the grid with the laser card if you have one. Also use it to install metal door frames, trust the aiming laser not the bubble on the spirit level. Use on a camera tripod to mount cabinets and countertops, align wood bases for cabinets and accessories, handrails and mirrors. I just used it on a tripod to set up a 600ft chair rail which saves a lot of time. Simply set up your tripod in the middle of the room, adjust the tripod to the desired height and walk towards it. Best little laser I've ever used. The micro adjustment knob is great for adjusting the line to fit the layout. It's a lot easier than moving the entire laser back and forth until you get lucky and hit your target. This 3 line laser with square line capability and micro adjustment makes it the best small laser I have used in my 30 year career. The only drawback is the lack of a pendulum lock, so it has to be handled carefully when transported or transported in a suitcase. The bag is good, fits and holds the laser well and has room for 4 extra batteries. Battery life is good. The best laser when a large rotor is not needed.