The Lee Company’s miniature calibrated IMH insert orifices are designed for both liquids and gases. According to the company, the 2.5- and 5.5-mm (0.098- and 0.216-in) diameter cartridge-style orifices are the smallest, self-retained flow restrictors available, and they are designed to provide more accuracy than a drilled hole. Accuracy is confirmed by 100% flow testing to ensure that every orifice is within ±5% of its nominal flow rate. Constructed of stainless steel, the IMH insert orifices are available in a range of flow rates with orifice sizes as small as 0.002 in (0.05 mm). Some models are offered with an integral safety screen. Lee’s controlled expansion principle offers simple installation, providing retention and creating a leak-tight seal that prevents bypass leakage.