27. series 68000-27 nvis yellow a incandesce series 68000-27 nvis yellow a incandesce Series 68000-1 NVIS Green A white l.e.d. · 2 Series 68000-2 NVIS Green A white l.e.d. · 3. Series 68000-3 NVIS Green A Green l.e.d. · 4. Series68000-4 NVIS .