A trundle wheel is essential to large-scale outdoor labs, by making long distances easy to measure. Just roll the wheel along the ground to measure linear distance. Our Deluxe Trundle Wheel has a metered counter, heavy-duty construction, telescoping handle, and a convenient carrying case for field study (measures in metric).Strong plastic spoke wheel 12.25 inch dia(320mm). Handle elongated 31 inch(790mm) long, pushed in for storage 19 inch(480mm)long. Supplied with a convenient carrying / storage case.