This helmet came with the bike I got from a pal; however, his head is smaller than mine, so this helmet is too small for me to put on. It is utilized, but is in great condition and hasn't been in a wreck. This is a great rate on an excellent aero helmet. The Giro Advantage 2 Aero helmet would be a fantastic addition to any person's race gear. It is a Medium size, 55-59 cm. E-mail or text me with questions ... I want to offer ASAP so will sell on a very first come, first served basis.