Tube Holder Quad Variable Flow, only Back Catalog number: 800075 Manufacturer: SENSIDYNE Availability: In the manufacturer's stock Price on request - + Recommended 800232 Tube Holder Kit, Deluxe (Single, Dual, Triple & Quad, all sizes) Price on request 200187 Tube Holder Adapter, 3/16" to 1/4" Ends Price on request 800165 Sorbent tube adapter nipple for Dual manifold High Flow Splitter Price on request