Basically, the Laser 400 emits infrared energy pulses that reflect off of a selected target and then returns to the instrument's optical receiver. Complex circuitry then measures the time between the emitted pulse and the received pulse. This time is translated into distance units and displayed to the user through a liquid crystal display (LCD).

The Laser 400 sports a roof-prism monocular with 8x multicoated optics and a 20mm objective lens. A single CR-2, 3-volt lithium battery (not included) powers this FDA class 1 laser-generating instrument. The unit includes an adjustable eyecup/diopter ring for focusing. An LCD is mounted inside the Laser 400, which displays crosshairs, a battery life indicator, distance measurement, and units of measure (yards/meters) when activated. The overall dimensions are 3.7" long x 2.8" high x 1.4" wide and weighs 7oz. A neck strap and carrying case are also included.

To operate the Laser 400 Rangefinder simply install a CR-2 battery and depress the power button. The LCD display should appear. At this time you may want to change the units of measure using the mode button (the button closest to your eye). Place the crosshairs on your desired target and press the power button again. Your yardage should be displayed - it is that simple!

My first test of the Laser 400 was aimed at the advertised ½-yard accuracy. I went to a local golf driving range and asked the owner if the distances were accurate. "Down to the yard", he stated so off I went. I would select a target, the 200 yard marker for example, take a reading, and then take a half step backward or forward to see if the distance would change by ½ yard. Without fail the Laser 400 measured every distance correctly and always detected the ½-yard variance. By the way, the owner was correct, all of his distances were accurate down to the yard.

For the next test I climbed a tree in the back yard and asked my son to move around to different locations in the yard. He had a tablet and pen with him and every time I told him to stop he would write down the reading I called out, tear out the paper and lay it on the ground. After taking approximately 30 readings we went to work verifying the yardages. The Laser 400 performed flawlessly.

 My next test was the real deal - hunting. While on stand I ranged a 20 yard and 30 yard perimeter and mentally marked it. My Pennsylvania buck gave me all the time in the world and let me range him real-time. He ranged at 16 yards before the shot. My arrow, which passed through the deer, stepped off at 17 yards from the base of my tree!  Noted was the simplicity of acquiring readings on a wide variety of targets. The only problem I noticed was the display visibility. The red LCD display was difficult to read in certain situations. 

Carrying the compact Laser 400 was easy and operation was simple and required only one hand. All in all this is a top-notch piece of equipment and well worth the space it uses in my pocket. For bow hunting I can't imagine anything better!

SPECIFICATIONS:

• Type: Roof-Prism Monocular
• Magnification: 8x
• Objective lens diameter: 20mm
• Angular field of view: 6.3° 
• Eye relief: 10.1mm
• Exit pupil: 2.5mm
• Diopter adjustment: ± 5m-1
• Laser Class: FDA class1/EN60825-1 Class 3-A
• Laser wavelength: 870nm
• Laser pulse duration: 13ns
• Laser beam divergence: V: 5°-8°, H: 25°- 36°
• Laser Output: 633mW(FDA) 8.5w(EN60825-1)
• Structure: water and dust resistant
• Operating temperature: -10°C to +50°C
• Operating humidity: 20 - 50%
• Power source: one CR2 lithium battery, 3v
• Dimensions: 3.7"L x 2.8"H x 1.4"W
• Weight: 7oz

Ease of Operation: 5 of 5
Can you push a button? It is that easy.

Value: 4 of 5
The value of the Laser 400 may not be apparent until you either miss a big buck because you did not have it or you score on a buck of a lifetime because you did. In either case the under $300.00 price will not be an issue! 

For information on this or any other Nikon product contact:

Nikon Inc.
1300 Walt Whitman Rd
Melville, NY 11747-3064
http://www.nikonusa.com