HOOK DRIVE GEAR _ 7.00mm HOLE (20 TEETH) that fits many Elna sewing machines included but not limited to the list below  
Part # 408101
    
fits: 
ELNA - LOTUS 14, LOTUS 22 & LOTUS 32, 14, 17, 22, 24, 27, 32, 34, 36, 37, 52, 57