Our Medical ruler is made of plastic.The size is 8.4"L X 1.9"W X 0.04"D.Promote your brand in the medical community with this goniometer, orthopedic ruler! Whether your aim is doctors, nurses or other providers, this ruler with a medical scale, pain scale and injection infusion dose is sure to be helpful to many professionals. Hand it out at hospitals, clinics and other locations for a standout promotion!