HR diagrams of pure-He tracks of Z = 0.0001 metallicity (left), Z = 0.001 (center), and Z = 0.01 (right). Dashed red and dash-dotted black lines indicate the beginning and end of the He-MS. Pink stars indicate the final location for a few highlighted masses, whose mass is indicated close to the He-ZAMS position in M_⊙. Diagonal dashed gray lines indicates constant stellar radii as labeled.