Book 10:

LED modules for spotlighting

March 2017: Book 10 Edition 1.0 is now published

Zhaga Book 10 defines a family of circular LED modules that have a small circular light-emitting surface (LES). Book 10 LED modules can be used with luminaire optics such as lenses and reflectors, and are typically used in spot-lighting applications.

Book 10 contains simplified and harmonized specifications for the LED modules that were previously described in older Zhaga specifications:

  • Book 3 (50-mm diameter LED modules)
  • Book 11 (35-mm diameter LED modules)

Book 10 modules can be standalone LED modules, or they can be constructed by combining a COB LED array (defined in Book 12) with an array holder.


For an overview of Book 10, watch the video below or download the presentation


Public downloads are available:

Download Book 10 (English) - Edition 1.0, March 2017

Book 10 effectively replaces Book 3 and Book 11. Book 3 and Book 11 are published and available for public download. However, these Books will be withdrawn in October 2017.

The Zhaga Consortium will review and update these specifications from time to time. To ensure you are aware of any updates to the Zhaga specifications, please subscribe to the Zhaga newsletter.

MORE details

There are two LED module categories with different outer diameters.

  • D35 = 35mm diameter (formerly Book 11)
  • D50 = 50mm diameter (formerly Book 3)

A range of light-emittng surface (LES) diameters is allowed. Details are given in the Tables below.

The LED modules operate with a separate LED driver (electronic control gear). They are typically fixed to a heat sink using screws. The light output is essentially Lambertian to enable the luminaire optics to shape the application’s desired light distribution from a defined input.

LED module dimensions

Book 10





diameter (mm)

Screw-hole separation

distance (mm)


height (mm)

D35 Book 11 35 25 3.5
D50 Book 3 50 35 7.2

Light-emitting surface (LES) categories

LES category

Minimum LES

diameter (mm)

Maximum LES

diameter (mm)


(Book 11)


(Book 3)

LES 6.3 >4.5 6.3 X  
LES 9 > 6.3 9.0 X X
LES 13.5 > 9.0 13.5 X X
LES 19 > 13.5 19.0   X
LES 23 > 19 23   X
LES 30 >23 30    
LES 40 >30 40