Only suitable for Rollick/Instant/Aster Dog Playpens.Floor Protectors: To protect your wooden floor from being scratched by the metal stakes, and also to reduce noise, the FXW Dog Playpen Floor Protector has been developed.Safety Design: It takes a little effort to put on the stakes, but after that, it is quite hard to come off by itself, which is the key point – this makes it unlikely that your pet could accidentally remove and swallow the sleeve.