Milwaukee AIR-TIP 1-1/4 in. - 2-1/2 in. Cross Brush Tool Wet/Dry Shop Vacuum Attachment (1-Piece) 49-90-2035 - The Home Depot
Superior Grade - Cross 4-Ways KF16 Flange Vacuum Adapter, All Ends with KF-16 (NW-16) Flange, Made of Stainless Steel 304, high Vacuum: Amazon.com: Industrial & Scientific
KF-25 4-Way Cross - GOLDLEAF SCIENTIFIC - These KF-25 4-way cross vacuum fittings follow ISO-KF standards and are commonly used to build foreline vacuum plumbing and process systems.