The Baader 2.25X Triplet Hyperion Zoom Barlow brings about even better performance amongst Hyperion Zoom Eyepieces. This Barlow can turn your eyepiece into a 3.5 - 10.5mm eyepiece in an instant. The included T-2 adpater allows coupling to any of the 1.25" eyepiece holder or can be directly linked to a 1.25" eyepieces threads with other included adapters. Bascially any eyepiece designed with a 1.25" thread can be used allowing wide variety of configurations to suit your needs when using the 2.25X Triplet Hyperion Zoom Barlow. When using a photo projection lens a T-Ring which coonects to the T-Adapter.