Ordering kit refills Gainsborough kits use a different numbering system for bottom pins than used for replacement bottom pins. Refer lookup table below. Pin # in kit Refill pin # Length PB0 #0 4.0 mm BP9 #1 4.5 mm PB8 #2 5.0 mm PB7 #3 5.5 mm PB6 #4 6.0 mm PB5 #5 6.5 mm PB4 #6 7.0 mm PB3 #7 7.5 mm PB2 #8 8.0 mm PB1 #9 N/A To avoid confusion, you may wish to order bottom pins by size (mm) rather than #number.