Faucet Adapter Hose Diamater?

[OCDP]

I walked into Home Depot today like a big dork... I'm not a handy man, at all. I admit it, I am freakin' clueless when it comes to this stuff.

I will be recieving an Aquasafe RO/DI unit this weekend, and need the faucet adapter for it. I went into HD asking for a "faucet adapter for a reverse osmosis unit" and got the odd stare. Then after explaining myself, the guy says I must have the diamater of the hose ? I don't know if I SHOULD know this, but I don't.. I am trying to figure this out ASAP before work gets out so I can stop there before heading home. So if you know, please let me know!


Thanks for the help...