Renthal Twinwall Handlebars - Villopoto Stewart 996-01 Bend

The revolutionary Twinwall® handlebar is an oversized diameter 1 1/8" (28.6mm)
handlebar which utilises two tubes, one within the other, borrowing principles
from aircraft design to give the best combination of lightness, strength and
safety.

Since their introduction in 1998, the Twinwall has been the handlebar of choice
for more professional race teams and has helped more riders win championships
than any other handlebar in the world.