16 x 125mm, 16ml Polystyrene Round Bottom Test Tubes With Screw Caps. 1400 RCF rating. Provides reliable containment of laboratory fluid samples. Falcon® (a Corning Brand) tubes are widely referenced in published procedures and protocols. Polystyrene tubes are best suited for procedures requiring high optical clarity. With screw cap. Sterile. Shelf Pack of 125, Case of 1000. Falcon® (a Corning Brand) #: 352025.