Explore Scientific 2in Achromatic Replacement Focuser. This Explore Scientific 2in Achromatic Doublet Focuser comes with a 1.25" compression ring eyepiece adapter for added versatility and a 10:1 micro-focusing knobs as well as a rough focus knob. The Explore Scientific 2in AR Series Focuser offers tension adjustment that allows you to lock and/or adjust the tension on the drawtube to increase or decrease the weight of the eyepiece. Specifications for Explore Scientific 2" AR Series Achromatic Doublet Focuser: Weight: 1.75lb; .79kg Diameter: 2" Length: 201mm Package Contents: Explore Scientific 2in AR Series Focuser Explore Scientific 2 Achromatic replacement focuser