1.Material:PP 2.Brand:WHB 3.Sterilized by gamma irradiation 4.WHB Freezing Tubes is a one-time laboratory consumables dedicated to storing biological samples 5.In the gas state of liquid nitrogen environment, can withstand low temperature to minus 187 ºC 6.Unique design of the external rotation to avoid the possibility of cross-contamination 7.A silicone pad is included inside the cap to prevent liquid leakage 8.The caps are available with a variety of color code for easy identification 9.The maximum centrifugal force up to 17000xg 10.The cap groove is easy to rotate the lid 11.Large of the marked area to facilitate writing 12.High transparency of the tube, easy to observe the sample  13.Round bottom design for easy pouring of liquid, reducing residue