Genie CH1800 is a standard-gauge knitting machine with 200 needles, 4.5 mm apart. Genie, the Magic knitter, CH-1800 is the same machine as the Corona CH1800 (maybe you got the machine without the case and the carriage and do not see the name “Corona” anywhere but only see “Genie” on the needlebed). Thus, read the corresponding post.