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 811-9903-50 Charcoal Tube, Coconut Shell, Jumbo, 200/800mg, 10x110mm, with end caps, 50Pack Price on request 800238 Tube Holder O-Ring Kit Price on request 800066-10 Tube Holder Collar Clip, for 1/4" OD, 1/8" ID Tubing (Packg of 10) Price on request