This jumper is made with two squares in granny spike stitch. It comes in sizes from baby to adult. This pattern is designed to be made to measure so any weight yarn and hook can be used.

Materials
Dk / weight 3 yarn or any weight yarn of your choosing as it is made to measure.

For my adult sized one I used 2 x Caron Cloud Cakes Shade Cloud Grey (695 metres per 240g)
1 x Emu dk shade Flint and 1 x Stylecraft Bambino Shade All at Sea

I used weight 3 yarn, a 4.5mm hook for the main jumper and a 3.5mm hook for the rib edging

Written in English US terms with abbreviations for UK

The PDF is 13 Pages and has plenty of photos and a link to YouTube tutorial.