Used this on my balcony secured with zip ties to prevent my cats from slipping under balcony railing. Being the railing is still too low and can be easily jumped by the cats they’re not allowed out there but I built them a catio to enjoy. This was used as an In Case of Emergency and they slipped out. I can not secure the top of railing for them unfortunately due to condo rules. It’s basically clear whiteish color not detectable at all from below. Very strong. Have really good scissors or something strong to cut it as needed. I would definitely recommend.