. The card contains UVB color test strips, which can detect the UVB strength of environmental light. Small size and easy to store. Suitable for reptile owners. Reusable, designed for detecting outdoor UVB levels or UVB testing on the card only. Type: UVB test card Size: 8.4 x 5.3 cm Material: PVC Package Contents: 10 x UV Test Card Only the above package content is included; other items are not part of this package. Note: Lighting and different displays may cause slight color variations between the image and the actual item. Measurement error allowance is +/- 1-3 cm. Instructions for use: Low and very low ultraviolet radiation levels are not harmful to the human body and do not require protection. UV levels at medium and above can damage skin and eyes and require protective measures. This card is made with UV-sensitive color-changing material that reacts only to ultraviolet light; visible light does not affect it. Place the UV-sensitive area of the card in direct sunlightthe stronger the UV in the sunlight, the darker the color change. This card is designed to test the intensity of ultraviolet rays in sunlight and can also be used to evaluate the effectiveness of UV-protective products. The card is reusable and serves as a helpful tool for outdoor activities, travel, and sun protection.