We are Manufacturer. The products has been Certificated by CE. Good operablity. Nanofil® Composite Shades: A1,A2,A3,A3.5,A4,B1,B2,B3,B4,C1,C2,C3,C4,D2,D3,D4·Average grain diameter of filling is 0.6um,filling ratio up to 79.2% w/w. ·Extremely low polymerization shrinkage(2.2%)·Anti-attrition ability is greatly strengthened.·Extremely high physical mechanical strength.·Not sticky to the instruments ...