svbony sv135 telescope eyepiece zoom 7 to 21mm 1.25 inch zoom eyepiece fully multi coated 6 element 4 group zoom lens telescope accessory for astronomic telescopes svbony <b>svbony sv135-this is definitely a must for beginners to start a good eyepiece collection.with this eyepiece, you can enjoy planetary astronomy without spending a lot of money.as a beginner;sv135 is great for starter astronomer!</b><br><br> <b>7mm-21mm linear continuous zoom</b><br> regarding the zoom action; it is stiff enough that you won't accidentally shift focal lengths; but it is also smooth enough that you can rotate it without holding the base of the eyepiece with your other hand<br><br> <b>high quality optical design</b><br> 6-element 4-group premium optical with fmc ultra high quality standard coating;it also ensures the transmission of light up to 97% while reducing the loss of light during transmission<br><br> <b>40-57°field of view</b><br> it also gives you a clear and bright angle of view while ensuring you get the magnification you need;compatible with any telescope that accepts 1.25 inch eyepieces<br><br> <b>m28.5*0.6 filter thread</b><br> sv135 zoom eyepiece has m28.5*0.6 threads on the bottom very convenient for connecting filter;works great for photography<br><br> <b>note:this zoom eyepiece just for 1.25inch telescope; can't match with spotting scope</b><br><br> <b>technical parameters:</b><br> focal length: 7-21mm<br> zoon type: linear<br> lens structure: 6pcs / 4group<br> eye relief: 18mm - 16.3mm<br> interpupillary dist.:15mm<br> barrel size: 1.25" <br> field of view: 57~40° <br> coatings: fully multi-coated-green <br> rubber eye guard: yes <br> meterial: metal<br> color: black<br> thread size: m28.5*0.6<br> overall length: 93mm<br> net weight: 133g / 4.67oz<br><br> <b>package include:</b><br> 1xsvbony sv135 7-21mm 1.25 inch eyepiece<br> 1xlens covers (objective and eyepiece)<br> 1xlens cleaning cloth<br>