Mortar trays are a type of container used to hold mortar, a mixture of cement, sand, and water used in construction. HODS is an acronym for Heavy Duty Outdoor Storage, which is the type of material used to make mortar trays. Mortar trays are designed to be durable and weather-resistant, making them ideal for outdoor use. They are also easy to clean and maintain, making them a popular choice for construction projects.