Joel
Great value for small diameter
I use the 2.7mm OD borescope for checking the inside of solitary bee nest tunnels, which sometimes requires a very small diameter. Other borescopes of similar size I looked at ran upwards of $2,000. If you are looking for a larger borescope, there are more economical options, but the 2.7mm OD scope is about the best value out there. Excellent quality too.
Word of warning if ordering from the US though, there might be extra shipping/tax charges upon receipt of the item.