THIS IS THE WRITTEN VERSION (with two more sizes) OF MY VEST TUTORIAL ON YOUTUBE.
You can either follow the two part tutorial there or use this written version.

Languages: English (Español muy pronto)

Materials you’ll need:
300 (450) 580gr super bulky weight yarn (100m in 100gr each)
8mm (US11) circular needles
9mm (US13) circular needles
2 stitch markers
Scissors and tapestry needle
Additional cable or scrap of yarn

Measurements:
S/M: 44 cm/17’’ width, 48 cm/19’’ length
L/XL: 54 cm/21’’ width, 58 cm/23’’ length
XXL/XXXL: 64 cm/25’’ width, 68 cm/27’’ length