The Premier Technical Euro Nymph line from RIO is built on a monofilament core that is stiff and slick to allow quick feeding of line with less line sag between the guides on the rod. It has an ultra-thin diameter to help with sensitivity and to facilitate super-quick hook sets. The core of the line extends past the end of the line to form a leader resulting in no knots to hang up in the guides. The level line can be cut on the back end allowing the angler to achieve the perfect length for your rig. The leader is .013 in diameter and is pink for better visibility. The leader is level so you can cut and tune it to different situations.