Its a roofing nail ....
@cwhitt ....have you had any tornadoes, or winds strong enough to take off roofs ? or ...see a lot of blue tarps on peoples roofs ?
these roofing nails are used to lay a tarp over a damaged roof ....
the way they work ...above the roof damage ...have to lift an entire row of shingles so the tarp can slide underneath the shingles ...by lifting a shingle upwards - you would hammer 1 of these roofing nails through tarp, into roof ... repeat until the entire top edge of tarp is secured to the roof
the round blue thing is suppose to self-seal any leaks.....
