Compatibility: Universal stainless steel screw thread Size S: slim butt Size M: classic butt Stability: Rubber inner-body and blocking system to support the rod FEATURES: Durability: universal stainless steel screw thread Support: rubber inner-body allowing for maximum rod support -Size S: Suitable for the slimmest butts (e.g.: Caperlan Suprem rod). -Size M: Suitable for most rods on the market.