These steel handlebars have completely separate right and left halves held in the center by two ribbed steel pieces when clamped in a stem.

This allows the mounting of Grip Shift shifters on the tops rather than on the ends of the drops.

Center section diameter is 25.8mm (1 inch)

Grip-Shift 2-piece steel handlebars, 44 cm x 25.8mm Used, $25.00

Part# grip-2piece-u41

44cm measured end-to-end

From the side

The point where the halves meet can be seen.