The M8A1 mat was developed to prevent this, omitting the pierced holes that exposed the soil beneath. This mat has a solid surface, strengthened by corrugations that also encouraged the drainage of rainwater. The mat size also changed to be .
The M8A1 mat was developed to prevent this, omitting the perforated holes that exposed the soil beneath. This mat has a solid surface, reinforced by ridges that also promoted rainwater drainage. The mat size also changed to be .