The h-4 headlamp conversion is the best thing you can do for your lighting! bright white light illuminates much further than stock headlamps, showing you the whole roadway. H-4's bolt directly in place of your headlamps. optional 100 watt bulbs are the ultimate. Note: h-4's are a must for us near-sighted drivers! if you have a 356 six volt system please specify and we will substitute the six volt bulbs. order two for a complete set. other higher wattage bulbs available.