Abstract: To existing two-part hair curlers, wherein said one part is a small radius-sized cylindrical core member which provides correspondingly small-radius curls or waves, and said second part is a larger-sized outer cylinder which provides larger curls or waves, the within improvements include providing the two parts with a cooperating longitudinal slot and a radial projection which interfit during the telescoping of these two parts together, with the result that inadvertent unraveling of the hair in curled relation on the core is obviated and the strand of hair attached thereto is effectively guided into the slot and thus into a proper position to be wound about the outer unit preparatory to providing said large curls or waves.