Rod Guide
From The Angler's Dictionary — your encyclopedia of fishing rods, reels, and tackle
A guide is a ring-shaped component mounted along the length of a fishing rod that directs the line from the reel to the rod tip. Guides reduce friction on the line during casts and retrieves, distribute the load along the blank during fish fights, and keep the line aligned with the rod's spine. A typical rod has 6-12 guides depending on length and style.
Guide frames are made from stainless steel, titanium, or aluminum, while the insert rings — the part the line actually contacts — are made from silicon carbide (SiC), aluminum oxide, or Alconite. SiC inserts are the premium standard, offering the lowest friction coefficient and best heat dissipation for braided line, which generates significant friction heat during fast retrieves or long fights. Fuji is the dominant guide manufacturer, with their SiC and Torzite rings appearing on most mid-to-premium rods.
Guide size decreases from the butt (largest, called the stripping guide or butt guide) toward the tip, funneling the line from the wide spool down to a narrow path. If a guide insert cracks or develops a groove, it will shred your line — run a cotton swab through each guide periodically to check for damage.