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 811-9984-50 Sorbent Tube, Porapak-R 6X70, 70/35, 50/BX Price on request 800066 Tube Holder Collar Clip, for 1/4" OD, 1/8" ID Tubi Price on request 800062-10 Tube Holder Housing End, 1/2" for 6mm OD (Packg of Price on request