Here’s a quick overview of what to look for, plus a sample product and some tips for choosing a good 120 W / 20,000 mAh 4‑in‑1 power bank.

✅ What to look for / specs to verify

When picking a 120 W, 20,000 mAh, “4‑in‑1 cable” power bank, check for these features to make sure it matches what you want:

Feature

Minimum / Ideal Spec

Why it matters

Output power

120 W or close (e.g. via USB‑C PD / QC / “Super Fast”)

To charge high‑power devices (like some laptops or fast‑charging phones)

Number and types of ports

4 outputs (USB‑C, USB‑A, Lightning, etc) or built‑in multi‑cable design

You asked for “4 cable type B type C 4in1” — you want flexibility

Capacity vs realistic output

20,000 mAh nominal (≈ 74 Wh at 3.7 V)

Real usable capacity will be lower depending on conversion losses

Display / indicator

LED % display or digital readout

Helps you see exactly how much juice is left

Safety & protections

Overcharge, overcurrent, overheat, short circuit protection

To protect both the power bank and your devices

Build / quality / certification

Use good cells, known brand if possible, certifications (CE, FCC)

Prevents fail / fire risk or fakes

Also note: many power banks will advertise a “max 120 W” but that might only be under certain conditions (single port usage, certain voltage/current, etc). When multiple devices are connected, available wattage per port often drops.