This is the Carrera GO!!! High Speed Curves Extension Pack

Contents:
4 - 1/45 Curves
Track Connection clips
Guardrail and clips

Measurements :
Inside diameter of curve is approximately 8.25 inches (25.4 mm)
Outside diameter of curve is approximately 18 inches (457.2 mm)

For use only with GO!!! and Digital 1/43

Part letter "F" in instruction booklet