Here’s a basic function summary to help select the best laser for your needs.
TLM 100- Will do basic calculations (areas, volumes, single distance, add/subtract). 1/4" Accuracy at 100ft.
TLM 200- Will do the basic calculations above, and track max and min distances. Also features a 2-Point Pythagoras calculation. 1/8” Accuracy at 100ft.
TLM 300- Has all the abilities of TML200 but also features advanced Pythagoras abilities, angle and trapezoid measuring, built in memory and history reading. It can mount onto a tripod and has a 2X viewfinder, and a bubble for horizontal leveling. A built-in sensor automatically detects positioning of flap. 1/16" Accuracy at 100ft.
The Leica Disto Laser Measuring Tool has 5 Models:
Disto A2- Will calculate addition, subtraction, area and volume, designed for indoor use. 1/8" Accuracy at 200ft.
Disto A3- Can do basic functions listed above, track min and max distances, and features a spirit-level for horizontal alignment. Measure distances up to 80m.
Disto A5- Can do basic functions listed above. Has Pythagoras ability for finding surface area. 2X viewfinder ideal for measuring long distances (~100m). 1/16" Accuracy at 650ft.
Disto A6- Can do basic functions listed above. Also features a Bluetooth data transfer that exports directly to Pocket PC or laptop programs (Word, Excel, AutoCad) 1/16" Accuracy at 650ft.
Disto A8- Can do basic functions listed above. Also features a tilt sensor to measure angles, horizontal distances and inaccessible height measurements. It can mount onto a tripod and has a 3X viewfinder. 1/8" Accuracy at 650ft.