Book 15:

Rectangular LED modules for use with lens arrays

Book 15 defines a family of rectangular LED modules that are intended to be used with arrays of lenses (also known as lens plates).

The modules require a separate LED driver (electronic control gear), and usually will be mounted on a heat sink.

Book 15 modules with lenses are typically used for outdoor lighting applications, including roadway, pathway and outdoor-area lighting.


Book 15 defines the maximum outline (demarcation) of the LED modules, as well as the mounting-hole positions. In total there are six categories of module, with three different sizes, depending on the number of LEDs in the array (see Table).

Category Number of LEDs

Maximum length

of module (mm)

Maximum width

of module (mm)

2x2-DA / DS 2 x 2 72.6 50
2x4-DA / DS 4 x 2 123.4 50
2x8-DA / DS 8 x 2 225.0 50

The modules have holes for alignment of the optics (lens arrays). Book 15 defines the position and size of these optical alignment features. The DA and DS categories differ by the quantity and position of alignment holes. The DA version is for a single lens array per module, while the DS version is for individual lenses (with possibly different characteristics) per LED.

Book 15 also defines the position of the light-emitting elements (LEDs). Zhaga specifies the centre position of the light-emitting surface (LES) of these elements. Crucially, the size of the light-emitting elements is not restricted. For each module, the LED pitch is 25.4 mm.


Book 15 is currently at the draft stage. Once it has been approved for use by Zhaga members, it will then be published in due course.

Companies are invited to participate in the development of this Zhaga specification. Please contact Zhaga’s Secretary General for more information.