Tube Holder Adapter, 3/16" to 1/4" Ends Back Catalog number: 200187 Manufacturer: SENSIDYNE Availability: In the manufacturer's stock Price on request - + Recommended 811-9983-50 Sorbent Tube, Porapak-Q 6X110, 150/75, 50/BX Price on request 800260 Single Tube Holder Kit, 7-10 x 150mm Price on request 800231 Tube Holder Kit, Quad Variable, 6 x 70mm Price on request