Only the Kuru Toga have this system. You might want to try the Pentel Orenz which is another approach, with the (retractable) metal sleeve following the lead. B

Only the Kuru Toga have this system. You might want to try the Pentel Orenz which is another approach, with the (retractable) metal sleeve following the lead. Both features seem to me to "get inbetween" me and the pencil while drawing, that control over sharpness is nice, even with 0.5 leads. So ultimately I prefer to go with the Graphgear or the Pentel 120 A3DX (cheap, light, comfortable, reliable, but no retractable tip).