Instant Chain Depth – Four high‑visibility colors reveal exactly how much chain is overboard, one interval at a time. Snap‑Fit, Tool‑Free – Links press between chain shots in seconds; no zip ties, paint, or guesswork. Windlass‑Safe Design – Low‑profile shape runs smoothly through most Maxwell, Lewmar, Muir, and similar gypsies. Marine‑Grade Build – UV‑stable, corrosion‑proof copolymer won't crack or fade after seasons in saltwater. Choose Your Size – Order the links that matches your chain: 1/4", 5⁄16", 3/8", 7/16", 1/2" (7 mm, 8 mm, 10 mm, 12mm,13 mm) for G30, G40, G43, or BBB (3B). 1‑Year Warranty – If a marker fails under normal use within 12 months, we'll replace it—no hassle. Snap‑on chain markers offer a durable, removable alternative to paint or plastic inserts. Each kit ships with four colors (yellow, green, blue, red) and a printed legend card so you can set 20 ft, 25 ft, or custom intervals. Precision‑molded and hand‑inspected in the USA from marine‑safe HD copolymer.