Package information: you will receive 4 goniometer physiotherapy in the package, which includes both inches and centimetres. The transparent design allows you to read easily and quickly without visual impairment and makes your work easier. Double scales: two rulers are in one body with different scales and 7 inches/18 cm long arms, which can be opened up to 14 inches/36 cm, making it perfect for your drawing and design requirements. A functional tool to your measurement and drawing needs in your . rotation: meter physiotherapy offers a rotation and can be used on different occasions, which is helpful to accurately determine the movement area of joints in physiotherapy, sports , etc. Wide applications: goniometer can be used to measure the movement area of joints such as elbows, knees and the of the , etc. They can also be used to create architectural and horizontal measurements. [Important gifts]These clear plastic goniometers are suitable for artists, builders, designers, , architects, teachers, engineers, students and other people who have drawing needs, and bring many amenities for their work, or lifetime. Material: PVC Color Package Contents: 4pcs goniometer Only the above package content, other are not included. Note: Light and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.