Question: Where can I Purchase a LED and LED Product?
Answer: Please contact us by email to, just let we know your address and also the intended to use of the LED, we will feedback to you.

Question: How much does LED Cost?
Answer: LED price varies depending on the product, application and quantity, we will suggest the most suitable product to you after receiving your enquiry.

Question: What products of Wah Wang comply with the Pb free and RoHS?
Answer: Wah Wang makes every effort to comply with the RoHS directive and provides the information that WW Series product have been tested and confirmed to be Pb-free and RoHS compliant.

Question: What is LED?
Answer: A lighting-emitting diode (LED) is a semiconductor device that emits incoherent narrow-spectrum light when electrically biased in the forward direction of p-n junction. The color of the emitted light depends on the composition and condition of the semi-conducting material used, and can be infrared, visible, or near-ultraviolet.

Question: What is forward voltage (Vf)?
Answer: Forward voltage (Vf) is the voltage across a diode for a given forward current.

Question: What is junction temperature?
Answer: A p-n junction is formed by combing N-type and P-type semiconductors together in a very close contact. The term junction refers to the region where the two types of semiconductor meet. The junction temperature refers to the temperature measured at p-n junction, which is also the core of an LED.

Question: What is Radiation angle or Viewing Angel (2θ½)?
Answer: The emission angle refers to as the 2θ½ indicates how focused the light is when emitted from the LED. This angle is determined by measuring the angle from direct on-axis to the angle where light intensity falls to half of the on-axis intensity, and multiplying this difference by 2. The choice of viewing angle also affects the LED output intensity.

Question: What is Lumens?
Answer: Lumens in an international unit that refers to the amount of light that a light source produces.

Question: What is wavelength (λd)?
Answer: Light could be split into many colors. The colors produced by light are arranged in a precise array or spectrum. The order of color is constant, and each color has a unique signature identifying its location in the spectrum. The signature of color is the wavelength of light.

Question: How do I compare the brightness of different LEDs?

Generally LED intensity is measured in mcd (mill candela).
It is always important to know the intensity in mcd and the full angle of illumination taken at specific drive current (measured in milliamps, mA). To accurately compare one LED to another, the Angle of Illumination and current levels must be the same. One must also be careful to verify the published specifications from any supplier.

Recently the latest technology wide-angle LEDs that put out light flux similar to incandescent bulbs have intensity readings called out in Lumens. These lumen readings, taken at a set drive current (mA), remain the same regardless of beam angle.