Neutral sand grain size

C4 from 0,04 to 0,1 mm            PG 2 from 0,05 to 0,1 mm
PN38 from 0,05 to 0,2 mm        PG 3 from 1 to 2 mm
PF15 from 0,08 to 0,4 mm        PG 4 from 1,25 to 2,5 mm
PF25 from 0,16 to 0,6 mm        PG 51 from 1,6 to  4 mm
PF35 from 0,315 to 0,8 mm
PF35T from 0,315 to 0,8 mm
PFM 35+ (White, gray) from 0,4 to 0,9 mm