Owlet sock size 1 or 2 by kg UK

What do the kg bands say on the UK/EU guide?

UK boxes still print pounds next to kilograms, which is why “size 1 or 2 by kg” is the search. Owlet’s Dream Sock user guide (the PDF linked from support) and the UK product page agree on the outer weight window: healthy infants 2.5–13.6 kg, ages 0–18 months. The two fabric sizes are a starting point from weight; the IFU says switch size based on actual fit because feet differ.

The guide’s tip is: if in doubt, start with the smaller size, then change if the straps do not land naturally on the fastener.

How do I choose size 1 or 2 from the straps?

Weight gets you to the right drawer. The straps tell you whether that drawer is honest. Owlet’s placement help and the IFU use the same test: do not stretch the straps to make a small sock work.

1. 1
   Match left and right Each size has an L and an R sock. The notch sits on the outside of the foot, behind the little toe, with the owl’s head toward the toes. A left sock on a right foot sits on the arch — the IFU flags that as a pressure risk.
2. 2
   Size up if the straps will not reach If either strap fails to meet the fastener without being pulled taut, try the larger sock. Stretching is how red marks start.
3. 3
   Size down if the straps overshoot If a strap runs past the fastener, try the smaller sock so the fabric sits snug, flat and without gaps.
4. 4
   Recheck after a growth spurt The IFU says the baby’s foot may not match the weight line. Recheck whenever you wash the sock, after illness, and as soon as yellow prompts cluster.

Why does the wrong size cause yellow prompts?

Owlet’s user guide describes a yellow prompt as a placement or “sock off” problem: the sensor could not get a good reading for at least 60 seconds. A sock that is too loose lets the windows lift; a sock that is too tight or on the wrong foot shifts the sensor off the outer edge. Either way the base sings a lullaby and the app nags — that is a fit fault, not a diagnosis.

NHS England’s 2018 patient safety alert on pulse-oximeter probes makes the same point in hospital language: probes for babies and children must be chosen by weight and site. The wrong probe can read up to 50% low or 30% high. A consumer sock is not that alert’s subject, but the physics is the same — light and skin have to meet where the designer aimed.

When should I stop Size 2 and stop the sock altogether?

• 13.6 kg or the largest sock no longer fits — IFU stop line, even if the child is still under 18 months.
• Every size is too small or too large — the IFU says discontinue even if age and weight look fine.
• Irritated skin — do not put a sock on a marked foot; that is the red-marks article, not a reason to cinch tighter.
• A clinician has set different rules — intended use is healthy infants without chronic heart or lung diagnoses.

In shortUse 5.4 kg as the Size 1 / Size 2 starting split, then believe the straps. Size up if they will not reach, size down if they overshoot, and stop at 13.6 kg. Wrong size is a leading reason for yellow lights and red skin — not a reason to stretch.