This e-book includes all 4 Ozzy Sweater patterns, The Ozzy Crew, The Ozzy V, the Ozzy Crew Cardigan and the Ozzy V cardigan. All 4 patterns use DK weight yarn and are very flexible in terms of materials. You can use a warm and wooly yarn like the Sonder Yarn Sunday Morning DK featured in the Ozzy Crew sample or a summer plant fiber yarn like the Willow DK I used in the Ozzy V sample. Gotta love that versatility!