18 x 2440 x 1220mm Moisture Resistant Medium-density Fibreboard
MDF
(Medium Density Fibre) board is a commonly used particle board. Moisture Resistant MDF is used in places with high humidity levels. In comparison to standard MDF, Moisture Resistant MDF (or MR MDF) contains a moisture-repellent resin which gives it a better moisture resistant rating. However, MR MDF shouldn't be mistaken to be water resistant as it's still prone to swelling and warping if in direct contact with such elements.