Surface gravity for a rotating charged black hole

Question

I have that the surface gravity (at the outer event horizon) for a Kerr-Newman black hole is $$ K_+ = \frac{r_+-r_-}{2(r_+^2+(J/M)^2)} = \frac{\sqrt{M^2-Q^2-J^2/M^2}}{2M^2-Q^2+2M\sqrt{M^2-Q^2-J^2/M^2}} $$ where $r_\pm$ are the outer and inner event horizons, $M$ is the mass, $Q$ is the charge, and $J$ is the angular momentum.

I have a simple question, almost too dumb to ask: what (natural) units are used here, such that $M$, $Q$, $r_\pm$, and $J/M$ are dimensionally equivalent?

Answer 1

Planck units $\hbar=G_N=c(=k_B)=1$ see f.e. http://www.scholarpedia.org/article/Bekenstein-Hawking_entropy equation (11) where $T=\kappa/(2 \pi)$ (in Planck units)