We started early since the ride to the border town takes 6 to 7 hours if the weather is good. Although there were plenty of clouds there was no rain when we started.
About two thirds of the way to Phuntsholing, I noticed a flashing red light on the instrument panel of the bike. It was the rear tire deflating fast. I knew it was a puncture since there was plenty of construction going on.
After stopping, and inspecting the tire we found a nail that was 20 cm in length, and about 1/2 cm in diameter logged in the tire. We didn't know the size until we pulled it out. We used the repair kit and inflated the tire, and monitored the pressure, thank god it was holding.