The Siren from Dspiae is a tempered glass file constructed from quality tempered glass with nanotechnology for superior toughness compared to standard materials. Single-direction texture ensures smoother polishing results. The file is equivalent to 10000 - 12000 grit sandpaper and has three variants. 
 
SF-15 is 110x13x3mm
MSF-13 is 90x13x3mm
SF-20: 165x20x3mm