I just went to the back of my truck and got a piece of the Cleerline for you. It is the single mode, 6 fiber, DB, armored cable. You can bend it into a pretty tight loop, enough to curve in a single gang box. And the pull strength on this stuff is amazing. That outer multi-core tube around the fiber, protects it extremely well.

The only problem is the cost. The tag line all these fiber companies keep giving is how fiber is almost the same cost as cat these days. But that isn't the cost of these Direct Burial Armored cables - which is what you are most likely needing fiber for.

Also, someone mentioned indoor/outdoor fiber. The 2 big brands in this category for CI installers, both have cable listed as indoor/outdoor and NEITHER is suitable for burial. Currently the only cable they make for burial (that I've seen) is the cable that is also armored.