This is a FAST knit and very wearable! The drop stitch begins at the back hem and spirals around until the front collar.
There is a small chart and a written description of the drop stitch pattern. It is easier than it looks. This garment is done all one piece, no sewing.

Advanced beginner

FINISHED MEASUREMENTS
This is a close fitting garment and has approximately 4-9cm/1 1⁄2 - 3 1⁄2ins ease.

Bust (approximately)
cm 85 (95, 105.5, 115.5, 126, 136)
in 33 1/2 (37 1/2, 41 1/2, 45 1/2, 49 1/2, 53 1/2)