Shinsei claims to be made from "the purest, cleanest fluorocarbon crystals available" creating "the most invisible fluorocarbon on the market. After spending a tireless amount of hours in research and development with a team of Japanese engineers we have developed the perfect combination of strength, stretch and durability."

I used to believe every fluorocarbon is pretty much the same. A few of the cheaper or bulk brands, I noticed, would chafe easily requiring them to be retied fairly often. Others were soft and stretched thin without really noticing, causing them to weaken faster. When fish broke the leader, it was always a disappointment. That's when I invested in Shinsei, and found it is indeed superior for the uses I put it through.

The big test for me is mangrove snapper. They are leader shy. My first trip offshore with big mangrove snapper fell victim to 40-pound Shinsei. Beside it they didn't want to touch a different brand of 40-pound leader or 40-pound monofilament. That's when I became a believer. The next trip I hooked a 300-pound bull shark on only 30-pound leader. I did my best to absolutely horse it in, and the leader held up! I couldn't believe it! Now I offer the premium leader material. Below is a basic chart of what I use it for.

Each spool comes in 27-yard increments.

Leader Size	Target Species
15 - pound	When I get desperate. Extremely light tackle mangrove & yellowtail snapper. Light gear, very clean water if they won't bite anything else but will eat chum.
20 - pound	Clean water inshore & flats fishing leader, live bait and artificial. Light tackle snapper & light jig heads for more bites offshore. Will get more bites.
25 - pound	Good inshore all-around leader for 3000 - 4000 size spinning reels snook, redfish & trout. Light end of bottom fishing leader for snapper. Good for medium jig heads & Hogballs.
30 - pound	All around good size for offshore jig head and bottom fishing for hogfish or snapper. Can withstand grouper with finesse. Good size for permit fishing with crabs as well.
40 - pound	Good free line size leader. Can hold up for tuna, cobia and amberjack on medium spinning reels. Bottom fishing with spinning reels I use 40-pound past 80-feet. Pairs great with 2-ounce Hogball XLs.
50 & 60 - pound	Light tarpon fishing. Good for when tuna and amberjack are being more aggressive. Good size for heavy snook fishing around structure. My preference for shallow water grouper fishing as well.
80 & 100 - pound	Heavy tarpon fishing. Heavy grouper digging on big tackle. If you're looking to wench fish in, this is the way to go. You will minimize bites on smaller fish, but that isn't a problem because you want the big stuff with big leader.
150 & 200 - pound	If you have to ask, don't buy it.