TJ,
Purchase the $27.50 O2PTIMASK™ kit from CH.com... The adult small size face mask will work just fine. In fact, the mouth tube that comes with this kit works even better and I find it's easier to breath straight from the green "T" manifold with no mask or mouthpiece. Less residual CO2 from exhaled breath.
You also need an oxygen regulator capable of delivering a flow rate of at least 25 liters/minute for faster aborts. I averaged around 40 liters/minute for the very fastest abort times using a 0-60 liter/minute Ingage™ regulator from Flotec Inc.
The following link will take you to the Flotec web site. I suggest the CGA-540 version of this regulator with 0-60 liter/minute selectable flow rates and a single DISS fitting for a demand valve should you want one in the future.
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The CGA-540 fitting works on the larger home oxygen cylinders (M/H/K) and you get the best bang for the buck with the larger cylinders. You'll only get three aborts out of a 700 liter E-size oxygen cylinder.
Here's a photo of my home oxygen therapy kit with InGage™ 0-60 liter/minute regulator, O2PTIMASK™ kit and Carnét Oxygen Demand Valve. Note there's no mask or mouthpiece attached to the O2PTIMASK™ green "T" manifold.
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Tell the folks at Flotec you're a cluster headache sufferer and that Pete Batcheller sent you. That won't get you a break on the price or me a kickback... but it will tell them you're a hurt'n scooter and need one of these beauties real fast...
They build these regulators to order for around $190 and It usually takes 10 days from the time you confirm the order and give them your credit card nums...
If you're more adventuresome and want to go a less costly route for a high flow regulator, drop by your local Harbor Freight Tools store and pick up one of their welders oxygen regulators for $35...
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There's no flow rate selector on these regulators so you'll need to do some trial and error to figure out the best regulated pressure to use... but that only takes a few minutes to figure out...
Take care,
V/R, Batch