I used this on my balcony for about a year. It comes with four used strings and one unused string. The used strings have been lightly washed, but still have some dirt. Other than that, there are no noticeable stains. The strings can be substituted with vinyl string, cable ties, etc. I liked it, but I'm selling it because I no longer need it due to moving. Please see below for reference. ・Size: 180 x 180cm ・Material: High-density polyethylene ・Color: Gray White ・3-year warranty, UV cut rate: approx. 70%, light遮光率・approx. 70%