Kowa's TE-9Z 20-60x Zoom Spotting Scope Eyepiece is compatible with TSN-82SV, TSN-660, and TSN-600 series spotting scopes to provide a wide magnification range that will satisfy most of your observational needs. Using a simple bayonet mount, it instals easily, and the knurled dial makes changing the zoom quick and sure. The TE-9Z features a wide apparent field of view ? 42-126 with 60mm and 66mm scopes and 40-126 with the 82mm scope ? and a 16/16.5mm eye relief value for comfortable glassing, even with eyewear. Specs: Magnification: 20-60x (TSN 600/660) 20-63x (TSN 82SV) Exit pupil: 3.0-1.0mm (TSN 600) 3.3-1.1mm (TSN 660) 3.9-1.3mm (TSN-82SV) Field of view at 1000M: 33.2-17.5M (TSN 600/660) 31-17M (TSN 82SV) Eye relief: 16.5-16mm Field of view: 1.9-1.0 degrees (TSN 600/660) 1.8-0.95 degrees (TSN 82SV) Relative brightness: 9.0-1.0 (TSN 600) 10.9-1.2 (TSN 660) 6.8-1.7 (TSN 82SV) Twilight Factor: 34.6-60.0 (TSN 600) 36.3-62.9 (TSN 660) 41.5-71.9 (TSN 82SV) Weight: 370g In the Box: Kowa TE-9Z 20-60x Zoom Spotting Scope Eyepiece