TP-L4BG features include:

GreenBeam® technology
Automatic line centering and grade zeroing.
RC***0 radio remote for complete control of all TP-L4BG functions from up to **0 feet away.
Industry's brightest LED line pivot locator.
Bright, easy-to-read rear display.
All metal, waterproof housing so you know it'll survive even under the toughest conditions.
Topcon's innovative Green Beam® technology gives you the advantage of a beam that's four times brighter than conventional beams. That means you never lose track of it - even in direct sunlight! With the TP-L4BG Green Beam® setups are faster and easier than ever before.

SPECIFICATIONS
Accuracy
horizontal     ± *0" arc seconds
temperature drift     1"/C arc seconds per degree C
Beam
type     **2 nanometers, Green Beam™ diode
power     IIIa class, 4.5 miliwatt

Operating Range
laser     5 to **0 meters
line range     ±*5%
range     **5% to **0%
remote control operation     **0 meters from front (in pipe), *5 from behind

Line Control
width     ±*5% degrees

Leveling
mechanical system     Absolute encoder
self leveling range     ±*0% degrees

Alignment
line centering     yes auto
grade zeroing     yes auto
plumb reference     LED

Power
source     4 D NiMH standard, 4 D-Size Alkaline optional
aproximate battery life     *5 standard hours, *2 optional hours

Environmental
Operating Temperature     **0° to **0° Celsius, 4° to ***2° Fahrenheit
Waterproof     At least *6.5 ft (5 m) for *4 hours
Waterproof     At least *6.5 ft (5 m) for *4 hours
Dimensions (LxWxH)     4.9" x *4.7" inches, **5 x **4 Millimeters
Weight     8.*1 pounds, 3.8 kg

Optional features
Rolling Indication: yes indication, ±4 range