These are ACER Racing Aerospace Grade 6AL4V Titanium Button Head M4x8 Bolts 4 pieces total.
These are super lightweight 4x8mm titanium screws and are made not from lower grade titanium but from the best Grade 5 6AL4V Titanium. We offer a complete line of M3, M4, M5 and M6 Titanium screws in button head, flat head and various lengths.