Adapter, for 5 tubes 30 – 50 mL round-bottom/50 mL conical, skirted (Please order adapter for 50 mL conical tubes skirted 5804 737 008 or 022654373 for U.S. and Canada.), for 500 mL rectangular bucket in Rotor A-4-81 and Rotor S-4x500, 2 pcs.