Here’s a concise breakdown of the Scientific Anglers 100 lb Blue 500 yd XTS Gel-Spun Backing with free US shipping:

Key Features:
– Strength: 100 lb test (designed for heavy-duty saltwater or big-game fishing).
– Material: XTS Gel-Spun Polyethylene (GSP) – Ultra-thin, high-strength, and abrasion-resistant.

SCIENTIFIC ANGLERS 100 LB BLUE 500 YD XTS GEL SPUN BACKING -  FREE US SHIPPING

– Color: Blue (high visibility for easy backing management).
– Length: 500 yards (suitable for large arbor reels or backing under heavy fly lines).
– Low Stretch: Minimal elongation for solid hook sets.
– Smooth Handling: Resists tangling and casts smoothly.
– Free US Shipping: Included with purchase (retailers like Amazon, TackleDirect, or SA’s official site may offer this).

Best Uses:
– Saltwater Fly Fishing: Tarpon, tuna, billfish, etc.
– Big Freshwater Species: Musky, large salmon/steelhead.
– Backing for Heavy Fly Lines: Pairs well with 10-14 wt setups.

Why Choose It?
– Scientific Anglers’ XTS technology ensures durability without bulk.
– Gel-spun fibers outperform traditional Dacron in strength-to-diameter ratio.

Where to Buy:
Check [Scientific Anglers’ website](https://www.scientificanglers.com), Amazon, or major fishing retailers like Bass Pro Shops. Confirm free shipping terms at checkout.

Let me know if you’d like comparisons or alternatives!