From the Winston website:
For 2015, Winston introduces the groundbreaking new WINSTON BORON III TH-MS MICROSPEY® rods, an innovative addition of three specialized light line Two-Handed trout models. With our Boron III technology, these new high performance rods perfectly combine the power of a Spey rod and the finesse of a trout rod to bring a whole new dimension to fishing big, open trout waters, as well as fishing for landlocked salmon and smallmouth bass in moving water.
These fast action rods excel in a range of situations, from covering big, broad rivers to dealing with tree-lined banks or demanding weather. Designed with extensive input from Spey casting expert Tom Larimer, and tested with enthusiastic endorsement from other Spey casting experts in the field, these innovative new Microspey® rods create a completely new category of fly rods for trout anglers in particular. They have a specialized grip that feels more trout rod than Spey, use slightly larger chrome guides than typical trout rods, and come with a larger tiptop that allows for the larger diameter of the Spey style lines. And, of course, come in longer lengths of 10 1/2′, 11′, and 11 1/2′ for 3-weight, 4-weight and 5-weight models respectively. Another breakthrough design with Boron III from Winston, designing fly rods for the world’s passionate anglers.
“The new Microspeys are the ultimate tool for light line two-handed fishing.” – Winston Pro Advisor, Tom Larimer