B: This one is much handier to carry.

A: Which is the better material?

B: I'd say either is good.

A: Why do you recommend this?

B: This is effective against a cold.

A: What can this do that that can't?

B: This is portable but that isn't.

A: What special features does this have?

B: this works without a battery, but that one needs one.

A: Will I save money if I buy a dozen?

B:  You can save about ten percent.

A: What's the strong point?

B: One of the best things about it is that it is easy to operate.