Screw cap microtube with O-ring, polypropylene medical grade material. Conical shape. pack of 500, tubes with caps suggested for tissue homogenization on Next Advance Bullet Blenders (NA-01, NA-01R), Talboy high through put homogenizer (OP-TH01 ) and other bead based tissue homogenizers, such as MPBio FastPrep24, Precellys24.