This is a Nel Filter sized for the Carita N-1 (5 pieces) #51001. Yagura large and small diameter 6.7 inches (17 cm), there is a "dimples" on the top of the filter for easy setup. Size indication: Since the circumference of 18.5 inches (470 mm) is the size of the filter top, it is compatible with the ring part of 6.7 inches (17 cm) in diameter. 1 filter, 4 pieces of the same shape are produced (press cut processing), sewing is done in Japan. The flannel fabric is made using our soft flannel fabric that is close to the filtration rate of the Kalitas Nell Filter.