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 installs 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.