Technical

5.11 Sizing Charts

FPS / MS / JOULE conversion

Joule -- FPS ---- MS

0.2 ---- 148 ---- 044,85
0.3 ---- 181 ---- 050,85
0.4 ---- 209 ---- 063,33
0.5 ---- 233 ---- 070,61
0.6 ---- 256 ---- 077,58
0.7 ---- 276 ---- 083,64
0.8 ---- 295 ---- 089,39
0.9 ---- 313 ---- 094,85
1.0 ---- 330 ---- 100,00
1.1 ---- 346 ---- 104,85
1.2 ---- 361 ---- 109,39
1.3 ---- 376 ---- 113,94
1.4 ---- 390 ---- 118,18
1.5 ---- 404 ---- 122,42
1.6 ---- 417 ---- 126,36
1.7 ---- 430 ---- 130,30
1.8 ---- 443 ---- 134,24
1.9 ---- 455 ---- 137,88
2.0 ---- 467 ---- 141,51
2.1 ---- 478 ---- 144,85
2.2 ---- 489 ---- 148,18
2.3 ---- 500 ---- 151,52
2.4 ---- 511 ---- 154,85
2.5 ---- 522 ---- 158,18
2.6 ---- 529 ---- 161,25
2.7 ---- 539 ---- 164.32
2.8 ---- 549 ---- 167,33
2.9 ---- 559 ---- 170,29
3.0 ---- 568 ---- 173,21
3.1 ---- 578 ---- 176,07
3.2 ---- 587 ---- 178,89
3.3 ---- 596 ---- 181,66
3.4 ---- 605 ---- 184,39

How to calculate the charging time of a battery

Cheap chargers often don't have an integrated shut off functionality when the battery is charged. So that the battery is not overcharged and damaged thereby, one can calculate the charging time as follows:

Loading time = (Capacity of the battery in mAh) / (Charging current in mA) * 1.3

Protection standards for spectacles & goggles

ANSI Z87.1
ANSI is the American National Standard that covers the basic requirements for personal eye as well as face protection to minimize e.g. accidents from impacts.

EN ISO 12312-1
EN ISO 12312-1:2013 is the European Standard that specifies the special requirements (mechanical, optical, and so on) for sunglasses and sunglare filters for protection against solar radiation for general use etc.

EN 166
The eye protection regarding the professional life is regulated with the norm EN166. It is the standard European norm for the personal eye protection specifications which classified the eye protection in detail.

MIL-PRF-31013
MIL-PRF-31013 is a US military standard for open spectacles and special performance protective eyewear to test its ballistic effectiveness.

MIL-DTL-43511D
MIL-DTL-43511D is a US military standard for closed goggles and special performance protective eyewear to test its ballistic effectiveness.

STANAG 2920/4296
The NATO abbreviation STANAG stands for Standardization Agreement which sets up conditions, terms, technical procedures etc. between the alliance members. This test, which is called V-50, is the adaption of standards for ballistic protection levels / testing of a glass that is shot with a special buckshot. The measured value is the arithmetic mean of the set of measured velocities.

Why is the front lens of my red dot sight at an angle?

Red Dot Lens Positioning: All red dot sights have an objective lens at the front of the unit that is spherical in shape. However, unlike a conventional riflescope, the objective lens in a red dot sight is positioned off axis and appears to be tilted when looking at the sight. This angle of the front lens allows the light generated by the battery powered LED light source inside the unit to be reflected back into the sight. The reflected light becomes the "dot" or aiming reference that the user sees when a red dot sight is switched on.


This engineered "bending" of light is what makes today's red-dot sights so popular and easy to use. Adhesive is used on the inside of the sight to secure the LED to the inside of the tube. By design, the led package intrudes slightly on the field of view.