what product do you use on aerial cable (2 pair) to insert the strand in for tension relief?
If it's wire with a seel messenger, use a Reliable (now Emerson Network Power) #5056 or 5058, depending upon whether it's a .109 or .134 diameter steel messenger. If it is just standard fiberglass supported ("flat") drop wire, then use their PRS-1 drop wire clamp. There is a company on e-bay called MELighting that has these for sale cheap in boxes of 25, but they are not PRS-1; they are the same thing made by another manufacturer.