New Sewing Machine Thread Subdivided White = Dia Feather Polyester #50 Black = Dia Feather Polyester #50 Each color, 1 bobbin x 4 pieces = 8 pieces total. Approximately 45m per spool. ◎ We consider 90% of the bobbin to be the winding amount, but please allow for variations exceeding 90%. Bobbin Size: Diameter - Approximately 20mm Height - Approximately 11.5mm Hole - Approximately 6.2mm Material - Transparent Plastic Please be aware that these bobbins are for subdivision. Only those who understand the above and the nature of the subdivided product, please purchase.