Fully welded tubular steel construction. Model DH440Z - Static storage stand with steel shoes fitted to the base preventing wearing of the tubes.Model DH443Z - As model DH440Z but with nylon top rollers to allow drainage from the side bung.Models DH442S - Mobile on 2 x 100mm fixed wheels & 2 x 75mm swivel castors.Model DH445S - As per DH442S but with nylon top rollers to aid drainage from the side bung.