The number after the L in the block name indicates the amount of blocks per square meter, so the L22 requires 22 blocks per square meter, while the L11 only requires 11. A larger block will require less blocks, while a smaller block will allow you to turn tighter corners in your design.
The block itself is a hollow core, vertically interlocking concrete block for erosion control, landscaping, land reclamation and urban upgrading and infrastructure. The wide range of plantable retaining wall blocks is tailored to create environmentally friendly domestic or industrial installations and to support sustainable development in soil stabilisation. Walls can range from light gravity walls to geogrid reinforced earth-retaining or heavy gravity, double skin walls.