Standard opening vials require 5mm inserts, Wide opening vials 6mm Inserts Shop Fisherbrand™ Micro-Insert, Clear Glass, for Wide Opening Vial at Fishersci.co.uk Fisherbrand™ Micro-Insert, Clear Glass, for Wide Opening Vial conical,0,1 mL Volume,<4 µL residual volume,31 mm height Fisherbrand™ Micro-Insert, Clear Glass, for Wide Opening