Blister pack of 5 flat plastic sewing machine spools 15 K

Blister pack of 5 flat plastic sewing machine spools 15 K. Height 11.80 mm - ø 20.30 mm. Today's sewing machines operate on a lockstitch pattern. So you need a top wire and a bottom wire. The upper thread is therefore supplied by the spool of thread that you place on your spool holder. The bobbin therefore provides the lower thread. The sewing machine bobbin therefore plays just as important a role as the upper thread.