You will need a cable needle.

Finished measurements:
Back: 14(15, 16, 17, 18)“ 35(38 ,40.5, 43, 46) cm
Length: 15.5(17, 18.5, 20, 21.5)” 39(43n 47n 51n 54) cm
Sleeve: 10(12, 13.5, 15, 17)“ 26(30, 34, 38, 43) cm
Raglan cap: 6( 6.5, 6.5, 7.5, 8)” 15(16 ,17, 18.5, 20) cm

Yarn used:
Rowan Softyak DK
A Driftwood #244 4(5, 6, 7, 8) balls
B Pampas # 235 1(1, 2, 2, 2) balls