hi, this is intermediate pattern and the patters are given very detailed for each and every row so even beginners can also make with understandable pattern, this is pattern is my own pattern and tested several times. those who are loving to make something different in sweaters can make this with the easy understandable pattern, in this the size of the back centre spiral part is 15” x 15” and how much you want you can make with the detailed descriptions of the pattern of crochet spiral sweater, is there any doubts customers can always welcome to ask, i am ready to ask for all queries. Happy crocheting!!