The Z446-500-A250F by Hermle is a 250 ml flat-bottom bottle insert for the Z446-04500 4×500 ml fixed-angle rotor on Hermle Z446 / Z446-K centrifuges. Supplied 2 per pack. Enables 250 ml flat-bottom bottles in a 500 ml rotor position at up to 8,000 rpm / 10,367 xg. For conical 250 ml bottles, see Z446-500-A250.