The walker ski slide makes walking easier and helps seniors walkers glide when in use. Easy to install and ready to use.Be sure to check the size before buying heavy duty walker leg skis. The caliber size of this model is: universal 1-1/8inch and 1inch. be careful to measure before buying, it does not apply to 3/4 inch models.Walker legs skis are made of heavy-duty, high-quality plastic, which is very heavy and stable after installation, not a light and inferior product. It is the upgrade of the tennis ball on the market, 3 major advantages: 1. more durable, not like the tennis ball models broken in a few days. 2. more secure, designed for walkers. 3. more clean and tidy, not like the tennis ball models accumulate dust and mess.These walker slides are suitable for indoor and outdoor, even on uneven indoor floors can slide, and perform well on hard surfaces outside. Can be used for a variety of floors: Carpet, Concrete, Tiles, Grass. normal use will not damage the wood floor, but need to be replaced periodically, because of severe wear and tear, may damage the wood floor in the slide.A quality replacement walker skateboard is a gift of silent companionship for the elderly/family. Best wishes for a speedy recovery after purchase and use.