Max grain weight: 13 kg is the max grain weight that the basket can fit.
However, this is affected by grain crush, grain type and variety. A mash plate on top of your grain bed may make it easier to manage these larger grain weights. If you're unsure how well your grain bill will fit then mashing up to 12kg is recommended.
Min grain weight: 3 kg is the minimum grain weight you should mash with.
Note that with larger batch volumes the water to grist ratio is high, so the time needed to mash may need to be extended and the water to grist ratio reduced.