Terrafix Blocks. Terrfix blocks are patented units that join together with a mortise and tenon
system, having two cone-shaped projections, which fit similarly shaped holes in the bottom of the
adjacent block. In addition, holes through the center of each block allow for stainless steel wire
connection of many individual blocks to form a large mat. The uniform interlocking of the 50 pound
units creates a neat, clean appearance (Figure 29).