UNI Clear Mono 3/0 Fly Tying Thread- UNI-Mono Thread is a translucent monofilament thread ideal for salt water flies and ribbing for nymph patterns. It is a fine, supple, monofilament with 200 yards on a spool. It is supple, fine and clear, .004" ( .10 mm.). Breaking strength is roughly 16 ounces. 100 yard spools.