Nitori Anti-Slip Fixing Pipes By inserting the extra fabric along with the fixing pipes into the gaps between the seat and the armrests/backrest, the fabric will be securely fixed and less likely to slip. I am selling these because I don't use them. ▪️Color: Black ▪️Shape: Cylindrical ▪️Material: 　Surface: PVA 　Core: Polypropylene ▪️Quantity: Set of 6 Thank you for looking.