1. Remove the old tire from two wheels and clean any remaining adhesive from the steering wheel. 2. Note: Do not use glue or other hard plastics. You can use all-purpose adhesive, 100% plastic adhesive, or neoprene-based adhesive. 3. After applying adhesive to the plastic, wait 58 minutes before attaching the wheel. Allow 2448 hours to fully cure before use. Positive vs. negative distinction: The treadmill mop pad is divided into two partsone that contacts the ground (called positive) and one that attaches to the wheels (called negative). When replacing the tire cover, ensure correct orientationdo not reverse the sides. Positive side: From the outside, the lines run vertically. Negative side: From the outside, the lines run horizontally. The positive side has less resistance; the negative side has greater resistance. If installed incorrectly, wear resistance decreases and lifespan may be reduced. Material: Plastic Color: Black Package Contents: 2 x Caster Wheels Note: This package includes only the items listed above. Other items are not included. Lighting and display differences may cause slight variations in color between the image and the actual item. Measurement error allowance is +/- 13 cm.