SV106 provides you with a compact & lightweight star guiding solution. SV106 60mm multi-use guide scope with Helical Focuser is an ideal addition to any astrophotographer's collection of gear. Works with most short-medium focal length imaging systems. Full metal structure. Suitable for lens barrels with diameters ranging from 43-70mm. 1.25" standard interface. Built-in brass ring for eyepiece protection. External M42*0.75 male thread - can be connected to SLR through T ring(not included in the package). Supplied with 3-point adjustment rings for accurate alignment. Compatible with most Synta/Orion/Sky-Watcher-style finder shoes & clamps. Nylon-tipped thumbscrews. Avoid scratches on the lens barrel. For precise aiming. SV172 Dew Heater Strip is a good partner during frigid winter temperatures, condensation, frost, dew or fog days with high humidity. It warmed up quickly, fast removed the condensation from your lens, and held an even warmness all night to keep your glass clear. There are a device to let you adjust from off-to-low-to-high modes. You can change the the temperature by adjusting the regulator to meet your different needs. It keeps the lens warm so it doesn't form condensation. Perfect for any nighttime long exposure photography. Effective for keeping dew or frost off of your lenses. It seems to work well even when the outside temperature is quite low. The max diameter it will fit is 76mm. You'll have the decide for your lens. The SV172 band is 320mm long and 50mm wide. The heated portion of the wrap does not span the entire length. About 240mm is heating, others for velcro purposes. 66g / 2.32oz net weight will not be a burden for your telescope or camera.