Solid rubber plunger with screwthread connection. Attaches to drain rods for general purpose domestic drain cleaning. Creates a build-up of pressure, forcing obstructions to clear. Compatible with Silverline Expert Drain Rod Set and most third party sets. Plunger diameter: 100mm. 16mm bore. Solid rubber plunger with screwthread connection. Attaches to drain rods for general purpose domestic drain cleaning. Creates a build-up of pressure, forcing obstructions to clear. Compatible with Silverline Expert Drain Rod Set and most third party sets. Plunger diameter: 100mm. 16mm bore.