DEW Heater Tape 400mm to Fit Telescopes with 127mm Outside Diameter

High quality heater bands compatible with all of our dew removal range.
To find the ideal length of tape for your instrument, simply measure the outside diameter of the lens or mirror cell, multiply the result by 3.14 to find the circumference and select the "exact" (see note below) or nearest larger size "Heater length" from the list. For example, say an 85mm refractor lens cell measures 110mm, so 110 x 3.14 = 345.4, therefore the best tape would be AC352 at 350mm long. NB: "exact" means not more that 10% undersized on the circumference for AC350 to AC352 and not more than 5% undersized for all the rest.