These are used to close off unused fitting connections on components such as Distro Plates and reservoirs.SpecificationsMaterial: Electroplated BrassThread: G 1/4in.Bykski logo: EmbossedCompatibilityLoop: Non-AluminumIncluded Parts1x Bykski G 1/4in. Knurled Plug1x Sealing O-ringWarningsOver-tightening is unnecessary and will result in difficult removal.Due to the internal finish, this part may not be compatible with DI water-based coolants and is NOT compatible with PrimoChill Opaque and VUE Coolant Series! Not responsible for any damage caused by or when using this product. Use at your own risk.