Core (continuous lines) and surface (dotted lines) rotation rates as a function of gravity for models with an initial velocity on the ZAMS of 50 km s^-1, which account for surface magnetic braking. Black, blue, red, and green lines indicate models with a solar-calibrated braking and an additional viscosity of 3 × 10⁴, 1 × 10⁴, 4 × 10³, and 3 × 10³ cm² s^-1, respectively. The red dot indicates the values of the core rotation rate and gravity determined for KIC 7341231, while the blue region indicates the upper limit for its surface rotation rate.