Set of 7 brass soldering tips for soldering irons working with 900M or T18 tips. The set includes the following items: Blade for M2 inserts Blade for M3 inserts Blade for M4 inserts Adapter blade for M5, M6, M8 tips Bit M5 Bit M6 Bit M8 The tips have grooves to identify the size. 2 grooves = M2 3 grooves = M3 4 grooves = M4 5 grooves = M5 6 grooves = M6 8 grooves = M8