These Adult IV Filters have acrylic housing with hydrophilic PES filters and hydrophobic PTFE vents. Part #28220 has a 0.2 micron membrane with clear housing. Part #28221 has a 1.2 micron membrane with transparent blue housing. The filters measure approximately 3 in. x 1/4 in. x 1-1/3 in. and contain two ports to fit 0.12 in to 0.125 in. OD tubing. The rectangular filters are molded with an arrow on one side to indicate direction of flow and are self priming to vent air in the line.