Used Berkley Vanish 2lb test over the weekend as tippet. At a diameter of .006 it is equal to 5x. Worked well for me all day with the exception of once. I was using a thingamabobber and had it rigged close to my double surgeons knot when setting the hook the line snapped at the indicator. I have heard of this happing with thingamabobbers but I dont know how true it is. I will continue to try this line besides that once the line seemed quite strong and definitely has a stronger breaking strenght than 2lbs.