Standard opening vials require 5mm inserts, Wide opening vials 6mm Inserts Shop Fisherbrand Micro-Insert, Clear Glass, for small opening vial at Fishersci.co.uk Fisherbrand™ Micro-Insert, Clear Glass, for small opening vial conical with polymer spring,0,1 mL ,<1 µL residual ,29 mm height Fisherbrand™ Micro-Insert, Clear Glass, for small opening vial | Fisher Scientific