The geocell is made of 1.5 mm thick polyethylene (HDPE) band, which is packed in bellows shape. The openings of the geocell can be filled with any small-textured material, usually gravel or soil.
The height of the geocell is chosen according to the slope gradient – the steeper the slope, the higher the geocell should be. In general, a 10cm – 15cm high geocell is sufficient.
You can find the installation instructions here.