The Vintage NOS (New Old Stock) Scientific Anglers Inc. Floating Fly Line – L-5-F Green 25 Yards is a classic fly fishing line from a well-respected brand in the angling world. Here’s what you should know about it:

Key Features:
– Brand: Scientific Anglers (a trusted name in fly fishing)
– Model/Designation: L-5-F (likely indicating line weight and taper)
– Type: Floating (stays on the water’s surface)
– Color: Green
– Length: 25 yards (shorter than modern standard 90-100 ft lines, possibly for backing or specialty use)
– Condition: NOS (New Old Stock) – Unused, possibly from an older production era.

Possible Era & Rarity:
– Scientific Anglers has been producing fly lines since the mid-20th century, and vintage lines like this are often sought after by collectors or anglers who appreciate classic gear.
– The L-5-F designation may follow an older numbering system (e.g., L for “level” or “light,” 5 for line weight, F for floating). Confirming exact specs may require cross-referencing old catalogs.

Potential Uses:
– Collector’s Item: Vintage fly fishing gear has a niche market.
– Functional Use: If in good condition (no cracking or dry rot), it could still be fished, though modern lines outperform in coating technology.
– Backing or Specialty Rig: The 25-yard length suggests it might have been designed for short-line techniques or as backing.

Things to Check:
1. Condition: Inspect for dryness, cracks, or stiffness (common in old PVC-coated lines).
2. Compatibility: Verify if it matches a modern 5-weight fly rod if intended for use.
3. Taper: Determine if it’s level, double-taper (DT), or weight-forward (WF)—older lines often had simpler tapers.

Vintage NOS Scientific Anglers Inc - Floating Fly Line - L-5-F Green 25 Yards

Value Estimate:
– As a collectible, it might fetch $20–$50+ depending on demand.
– As a functional line, less if the coating is degraded.

If you’re looking to sell, use, or verify its specs, consulting a vintage fly fishing forum (like [Classic Fly Rod Forum](http://classicflyrodforum.com)) or checking old Scientific Anglers catalogs could help.

Would you like help identifying its exact age or taper? If so, photos of any markings or packaging would be useful!