Feature 1Improve Sitting Posture: This sitting posture corrector is perfect for students to correct their sitting posture, protect their eyes and spine, and allow them to grow healthily. 2Easy To Install And Use: Just clip the base part on the table, then adjust the height of the corrector according to the child's height, the adjustable height range is 5.9-8.3in. 3Avoid Visual Impairment: Helps improve bone deformation caused by wrong sitting posture, avoid visual impairment, and also cultivate good sitting habits. 4Full Viewing Angle: No blocking line of sight, keep your child in a good sitting position without constant reminders, protects vision and contributes to the normal development of the spine. 5Exquisite Workmanship: Attention to details, finely polished button, non slip base, adopts soft silicone material, skin friendly, comfortable to use.SpecificationItem Type: Sitting Posture CorrectorMaterial: PP+ABS+SiliconeAdjustable Height Range: Approx. 15-21cm / 5.9-8.3inCan be clipped on the table .wang-edit-text{ font-family:'Arial' !important; } .wang-edit-text table { border-top: 1px solid #000; border-left: 1px solid #000; } .wang-edit-text table td, .wang-edit-text table th { border-bottom: 1px solid #000; border-right: 1px solid #000; padding: 3px 5px; } .wang-edit-text table th { text-align: center; }Package List1 x Corrector1 x BaseNotePlease allow slight error due to manual measurement. Thanks for your understanding.