Petzl reinvented the headlamp with the Iko Core: out goes the classic housing sitting on an elastic band, in comes an ultra-flat AIRFIT headband with the battery moved to the back. Released in late 2020, it's still a benchmark in the ultralight segment, yet it was missing from the RunMorph catalog even though the Nao RL and Swift RL were already there.
© Petzl, official photo used for editorial purposes
The Iko Core is a 79-gram headlamp that breaks the category's rules with its semi-rigid AIRFIT headband and a rechargeable CORE battery mounted at the back of the head. It puts out 500 lumens in max mode for 2 h 30 min of battery life, runs up to 100 hours in economy mode, and turns into a lantern with its storage pouch. The Hybrid Concept also lets you switch to 3 AAA batteries in a pinch, a real plus for self-sufficiency, though power drops to 350 lumens.
Petzl has dominated the outdoor headlamp market for decades, and RunMorph already covers its Nao RL and Swift RL. The Iko Core plays in a different, complementary segment. Instead of chasing raw power or reactive lighting, it goes all in on lightness and comfort, with a concept that breaks radically from the classic housing on an elastic band.
The patented AIRFIT headband is semi-rigid and ultra-flat, so it packs flat in a bag instead of tangling like a classic elastic band. The rechargeable CORE battery sits at the back of the skull, spreading the weight across your whole head instead of loading it onto your forehead. The result: a claimed 79 grams, 87 to 90 grams on the scale with pouch and cable depending on the tester, and a headlamp you quickly forget once it's on.
| Brand | Petzl |
| Model | Iko Core |
| Power | 500 lm (Max Power) / 100 lm (Standard) / 6 lm (Max Burn Time) |
| Beam distance | 100 m / 45 m / 10 m depending on mode |
| Battery life | 2 h 30 min / 9 h / 100 h depending on mode |
| Weight | 79 g (claimed), up to 90 g with batteries on real-world scales |
| Power source | Rechargeable 1250 mAh CORE battery (included) or 3 AAA/LR03 batteries (Hybrid Concept) |
| Power on AAA batteries | 350 lm max (vs 500 lm on the CORE battery) |
| Charging | Micro-USB cable, about 3 h for a full charge |
| Water resistance | IPX4 (weather-resistant) |
| Beam type | Wide or mixed, 7 LEDs |
| Headband | Semi-rigid, ultra-flat AIRFIT, adjusted with a rear cord |
| Warranty | 5 years on the lamp, 2 years on the battery |
| Official price | About €80 (€78.50 to €89.90 depending on source and period) |
The lamp folds up and slips into the included storage pouch, which doubles as a diffuser to turn the Iko Core into a camp lantern.
The Hybrid Concept is the Iko Core's most tangible selling point. The lamp automatically detects whether it's running on the CORE battery or 3 standard AAA batteries and adjusts its power accordingly (500 lm on the battery, 350 lm on AAAs). That's a real safety net for long runs or trips where recharging a proprietary battery isn't always an option.
The AIRFIT headband is also a game changer for comfort. Its semi-rigid, ultra-thin shape lets air, sweat and rain pass through, unlike a classic elastic band that clamps down on your skull. You adjust it with a cord at the back, locked by a simple single push-button.
© Petzl, official photo used for editorial purposes
RunMorph's advice: Max Burn Time mode at 6 lumens is plenty on a clear night. Save the 500-lumen mode for technical sections or scanning far ahead instead of running it nonstop.
Independent field tests agree on the essentials: the Iko Core's comfort and low weight earn unanimous praise. One test run over several months, from an island crossing to regular early-morning training, calls it the most polished headlamp the tester has used, scores it 18/20 and rates the light as sufficient in every condition encountered. A second, more measured field test confirms the exceptional comfort and ease of use (9/10) but spells out concrete reservations instead of glossing over them. Micro-USB charging instead of USB-C already felt dated in 2020. There's no red-light mode to preserve night vision. And lantern mode falls short in practice: the storage pouch is too opaque, and the lamp's shape makes it awkward to set on the ground without hanging it up.
The gap between these two reviews isn't a contradiction, just a matter of degree. Both confirm the same everyday comfort and reliability; one stops at enthusiasm, the other digs into the details of real-world use. A third, triathlon-focused test confirms the same strengths (power-to-weight ratio, single-button simplicity, the handy pouch-lantern bonus) without flagging any additional major flaw.
| Criterion | Petzl Iko Core | Petzl Swift RL |
|---|---|---|
| Max power | 500 lm | 1100 lm |
| Weight | 79 g | 100 g |
| Key technology | AIRFIT headband + Hybrid Concept (battery/AAA) | Reactive Lighting (power adapted to cadence) |
| Beam | Wide or mixed, no long-range spot mode | Reactive, mixed close/distance |
| Backup power | 3 AAA/LR03 batteries | Rechargeable Accu battery, no AAA backup |
The Swift RL targets technical trail with more power and responsiveness, while the Iko Core goes all in on comfort and battery/AAA versatility for steadier outings, bivouacs or everyday running. The two complement each other more than they compete head-on.
The Iko Core is for runners who want to forget they're wearing a headlamp on early-morning runs, at a hut or on a bivouac, and who don't need a long-range spot for technical trail at night. For that job, the Swift RL or the Nao RL are better equipped, with more power and reactive lighting.
Running early in the morning or late at night also takes discipline in how you structure your sessions. The RunMorph training plans help you frame your runs, with or without a headlamp.
The Iko Core remains a benchmark for comfort and lightness, and its concept still hasn't aged, years after launch: the AIRFIT headband, rear-mounted battery and battery/AAA versatility add up to a coherent, well-thought-out package. Micro-USB and the lack of a red mode are the only real complaints that come out of the field tests.
8/10. A headlamp that's still relevant if you put comfort and versatility ahead of raw power. For demanding technical trail at night, the Swift RL remains the better Petzl pick.