Thinking of going to a single-ring setup on your Offset Double crank? This is the chainring guard you want to pair with your Surly Narrow-Wide Chainring. It mounts cleanly to the four spider arms on your crankset using integrated threads and the included chainring bolts - no nuts required! This aluminum guard will cover chainrings up to 30 teeth, makes your 1x setup look clean and gives those spider arms something to do. Nobody likes a bored spider.