The FF1 blue plug is collared for fixing of hard materials such as steel|The stainless steel flanged hex head screw (also with T40) can be installed using a hex socket|Internal plug geometry designed to fit the screw head|Plug design ensures multi-axis expansion|Embedment depth markings facilitate precise installation|Specially-formulated nylon allows best performance installation for use in all base material categories according to ETAG 020 (A, B, C, D)