Dryalite Headlight Moisture-Fix Kit (Pair) – fits BMW F20/F21 – Hella 159 333 00
Dryalite absorbs humidity from the air inside your headlight. Choose your vehicle to find the right kit.
Kit: £50.00 - Available.
Fitment and specification
Dryalite® Headlight Moisture-Fix Kit (Pair)
BMW 1 Series F20 / F21 (2011–2019) — TOP/UPPER engine-bay headlight cap
- ✓ Helps reduce condensation by drying the air inside the headlight
- ✓ Quick DIY fitment (typically under 2 minutes per side)
- ✓ Protects expensive headlights from recurring moisture build-up
IMPORTANT: FIT CHECK (10 seconds)
This listing is for the TOP/UPPER cap that is accessible from the engine bay.
✅ Fits ONLY if your existing top cap is marked: 159 333 00 .
❌ If your cap shows a different number (e.g. HELLA 19291300), please view my other listing.
Please check to the reference image in the listing: if you are unsure, message me a clear photo of your cap before ordering and I’ll confirm.
What’s Included
- 2 × Dryalite® moisture-fix caps (left + right)
- 2 × 50g silica gel desiccant packs
Seal: Re-use the original foam gasket/seal from your BMW cap (no new O-ring supplied).
How It Works
Dryalite replaces your top access cap and holds desiccant inside the headlight area to absorb humidity. If condensation returns over time, you can dry and re-use the desiccant.
Re-activating the Desiccant
Microwave: 3–5 minutes at 700W (use a microwave-safe dish; do not microwave any plastic packaging).
Oven: 30–60 minutes at 100–120°C.
30-day money-back guarantee
How does Dryalite reduce condensation?
Dryalite holds moisture-absorbing silica gel inside vehicle-specific headlight caps. It absorbs water vapour from the air inside the headlight, leaving less moisture available to condense on the lens.
Twist-off cap kits need no cutting or drilling. The sealed-cap F10 kit uses a different fitting method explained in its product details.
Recurring misting, not active leaks. If the headlight is cracked or has pools of water inside, Dryalite will not fix it. Repair the fault first.
Green means recharge.
Remove the silica packets, dry them until the beads turn orange, let them cool, then put them back.
30-day full-refund guarantee
If it does not help, return your kit within 30 days for a full refund.
Questions before ordering.
Will Dryalite fix every condensation problem?
No. Dryalite absorbs humidity from the air inside the headlight. It cannot repair a cracked headlight or deal with pools of water inside it.
Is the silica gel loose inside the headlight?
No. The silica packets sit securely inside the Dryalite cap, away from the bulb and reflector.
How quickly should I see a difference?
Some buyers see an improvement within hours. Allow a few days, as every headlight starts with a different amount of moisture.
Can I dry my headlights with a hairdryer before fitting Dryalite?
Warming a headlight can clear visible mist temporarily, but it does not necessarily remove the moisture: droplets may simply turn back into water vapour. If you choose to use a hairdryer, follow your vehicle manufacturer’s guidance and avoid high heat, which can damage plastic, seals or electronics. Let the headlight and the air inside cool to ambient temperature in a clean, dry, sheltered place before refitting the caps. Warm air can contain more water vapour before condensation forms; if warm, moist air is trapped inside, misting can return as the lens cools. Cooling alone does not remove moisture. Dryalite absorbs water vapour to help lower humidity after fitting.
Why use Dryalite instead of leaving the dust caps off?
Removing a dust cap may help moisture escape temporarily, but leaving it off also exposes the headlight to dust, debris and water splashes. It does not actively absorb moisture, and damp outside air can enter again. A correctly fitted Dryalite cap with an intact seal keeps the access opening covered while silica gel absorbs water vapour inside. This helps manage humidity while keeping debris out, rather than leaving the headlight open. Keep the headlight’s original ventilation paths clear, and repair damaged housings or seals first.
How do I choose the right kit?
Choose your model above and compare the product photos with your headlight cap. Contact us if you want help checking.
Can the silica gel be reused?
Yes. Orange means ready and green means saturated. When the beads turn green, remove and dry the silica packets, let them cool fully, then refit them. Never heat the caps or seals.
Do I need to permanently modify my headlights?
Twist-off cap kits require no permanent modification. The sealed-cap F10 kit uses a different fitting method, so check its product details before ordering.
How often will the silica need recharging?
It depends on the weather and your headlight. Check the indicator beads and recharge only when they turn green.
What if Dryalite does not help?
Return the kit within 30 days for a full refund.