FLEXTAIL's pumps weigh less than a bar of soap and inflate a sleeping pad in under a minute, which is why they have quietly become standard kit for people who count grams. The brand now sells two main versions and the shop pages do not make the choice between them obvious.

The decision comes down to one specification most listings bury: maximum air pressure. The Tiny Pump 2X delivers 4 kPa. The Zero Pump delivers 2.5 kPa. Both move the same volume of air at 180 litres a minute, so both fill a pad quickly, but the Zero Pump runs out of pressure sooner at the firm end.

If you sleep on a soft pad, that difference is irrelevant and the Zero Pump's lighter weight wins. If you like your pad firm, or own a thicker winter pad, it is the whole decision.

Verdict in one minute

1. Tiny Pump 2X: 96g, 4 kPa, 1300mAh built-in battery, plus a 400 lumen light, a vacuum mode and a magnet. The more useful tool.
2. Zero Pump: 62g, 2.5 kPa, 650mAh removable battery, no light. The lighter option for people who already carry a headtorch.
3. The removable battery on the Zero Pump is its best feature, because you can carry a spare on long trips.
4. Both are loud. The Tiny Pump 2X has a high pitched whine and the Zero Pump is only slightly quieter.
5. Check your pad's valve against the included adapters before you rely on either. Fit complaints exist.

The pressure question, in practical terms

Air pumps are rated by volume and by pressure, and they do different jobs. Volume fills the pad. Pressure is what lets the pump keep pushing air in once the pad is already mostly full and resisting.

Both FLEXTAIL pumps shift 180 litres a minute, which is why both get a pad from flat to nearly full in around 45 to 50 seconds. What separates them is the last ten percent. At 4 kPa the Tiny Pump 2X can push a pad to a genuinely firm finish. At 2.5 kPa the Zero Pump gets you most of the way and then starts to struggle, and users have reported needing additional breaths to reach the firmness they wanted.

One user comparison noted the Zero Pump's maximum pressure is lower even than the original Tiny Pump, not just the 2X. So the Zero is the newest model and not the most capable one, which is the opposite of what a product line usually implies.

Translate that into your own kit: an ultralight pad used at a soft setting will inflate fine on either. A thick insulated winter pad, or a pad you inflate hard because you are a side sleeper who bottoms out, is a Tiny Pump 2X job.

FLEXTAIL Tiny Pump 2X

3.38 oz / 96g. 1.8 x 1.7 x 2.3 inches. 4 kPa, 180 L/min, 1300mAh.

The more complete device, and for most people the right buy despite being heavier. It is not just a pump.

1. A built-in light at 40, 160 or 400 lumens, with up to ten hours at the lowest setting. At 400 lumens it is a usable tent lantern, not a token LED.
2. A vacuum mode that sucks air out, which deflates pads properly and compresses clothing or sleeping bags into stuff sacks. This is genuinely useful and the Zero Pump cannot do it.
3. A metal hanging handle and a magnet, so it attaches to a tent loop or a metal surface rather than rolling into the dirt.
4. Around 32 pad inflations per charge in independent testing, against FLEXTAIL's claim of 40 plus.

Two things to plan for. The light and the pump share one battery, so nightly lantern use eats the inflation capacity, and on a long trip you should treat the 32 fills figure as optimistic if you are also using it for light. And it is loud. Reviewers describe a high pitched whine and nobody calls it quiet, so if you are inflating at a busy campsite after dark, expect to be noticed.

FLEXTAIL Zero Pump

2.2 oz / 62g including pump, battery, lanyard and nozzle. 2.95 x 1.02 inches. 2.5 kPa, 180 L/min, 650mAh.

Thirty four grams lighter than the 2X, which is a real saving if you are weighing your kit, and nothing if you are not. It does one job: pumping.

The feature worth buying it for is the removable, rechargeable battery. Around 25 fills per charge sounds limiting until you realise you can carry a spare cell, which effectively makes the capacity whatever you want it to be. On a long trip without power, a swappable battery beats a larger sealed one.

Reported problems to be aware of, from user comments rather than the brand:

1. Lower maximum pressure than both the 2X and the original Tiny Pump, requiring additional breaths to finish a firm pad.
2. At least one user reported the pump cutting off early and needing the button pressed repeatedly to continue.
3. At least one user reported the included adapters not fitting their mattress valve.
4. Its small size makes it easier to lose. A 62g object in a dark tent is genuinely easy to misplace, which is what the lanyard is for.

Check your valve before you buy

The most avoidable disappointment with any of these pumps, and it takes two minutes.

Sleeping pad valves are not standardised. Therm-a-Rest WingLock, Sea to Summit, Exped, Nemo and Klymit all differ, and cheaper pads often use their own. FLEXTAIL supplies a set of adapters, and users have reported them not fitting.

Before ordering, photograph your pad's valve, measure its internal diameter, and compare against the adapter set shown on the listing. If your pad came with its own inflation sack adapter, check whether that connects to anything in the kit. If you own several pads, check the one with the most unusual valve rather than the easiest one.

Living with the noise

Worth a short section because it is the one complaint common to both models and it surprises people.

These pumps use a small high speed fan, and small plus fast equals high frequency noise. There is no quiet version of this physics at 180 litres a minute in a 62 gram package. The Zero Pump is marginally quieter and neither is discreet.

Practically: inflate before quiet hours rather than at midnight, hold the pump against the pad rather than letting it rattle, and accept roughly 45 seconds of whine. For the time saved and the weight carried, most people consider it a fair trade.

Before you order

1. Decide on pressure first. Firm pad or winter pad means the Tiny Pump 2X. Soft summer pad means either.

2. Check whether you already carry a headtorch or lantern. If you do, the 2X's light is a duplicate and the Zero's weight saving gets more attractive.

3. Verify your pad valve against the adapter set.

4. If you want vacuum compression for your sleeping bag or clothing, only the 2X does it.

5. Note that both are made in China and carry roughly a one year warranty depending on where you buy. Keep the receipt and check the warranty with your specific retailer, since regional distributors differ.

Worth buying if

1. You inflate a pad most nights and are tired of either a pump sack or getting lightheaded.
2. You want one device that inflates, deflates, compresses gear and lights a tent, in which case the 2X is excellent value.
3. You are counting grams and already carry a light, which makes the Zero Pump the right call.
4. You are going out for more than a few nights without power and value a swappable battery.

Skip it if

1. You camp from a car with mains or 12V power available, where a larger and cheaper pump does the job better.
2. Your pad has an unusual valve the adapters do not fit.
3. Noise at a shared campsite is a real concern for you.
4. You inflate a pad twice a year, in which case the pump sack that came with the pad is free and adequate.

Final word

FLEXTAIL makes a genuinely clever bit of kit and the Tiny Pump 2X is the version most people should buy, because the light and the vacuum mode turn a single purpose gadget into something that earns its place in a pack.

The Zero Pump is for a narrower buyer: someone weighing their kit who already has a light, wants a spare battery, and sleeps on a pad that does not need the extra pressure. If that is not you, the 34 gram saving is not worth giving up the three things the 2X does that the Zero cannot.