An Audette Collection Exclusive
These bulbs, manufactured in Germany (one of the few H4 halogen bulbs not made in Asia), deliver 190% (+150% stated on the box but they test at +190%) more illumination than a standard 60w/55w H4 bulb. That's 190% brighter with no increase in current draw or heat generated. As a result they don't require the installation of a relay kit as is required by the standard 100/55w H4 bulbs. There is one small compromise - they don't last as long as standard H4 bulbs.
These are a simple plug n' play replacement for your current H4 bulbs.
Daniel's Analysis of These Bulbs
These bulbs are made specifically and exclusively to my specs. They're based on the Vosla H4 +150 quartz bulb, but _without_ that bulb's light-blocking blue tint, meaning significantly more light reaches the road. They were spec'ed to approximate the much-loved and long-discontinued Osram 64205 bulb, which was nominally (optimistically) rated at 2000/1350 lumens and, realistically-tested, consistently provided around 1900/1200.
Result: the new Vosla bulb is giving between 2100 and 2200 lumens on high beam, and between 1195 and 1220 lumens on low beam. We nailed it! For all intents and purposes this is the Osram 64205 brought back, but with longer lifespan because of better capsule and fill gas technology, and better beam focus because of better filament-focus precision.
#1: Be careful if you buy this bulb somewhere else. These bulbs have been built specifically to Daniel Stern's specifications, and are only available through AC. What is being sold elsewhere (at Amazon for example) are knock-offs made by Technical Precision. While those may be fine, they under-perform the bulbs built to Daniel's specs.
#2: Please do not use LED bulbs in reflector headlights like these bulbs are designed for. You may have noted that we do not sell individual LED headlight bulbs for that reason. If they worked properly we would sell them. Click here for the details on why they are a disaster from Daniel Stern.