Usually, what I do is I try to make sure that I have the maximum product knowledge that whatever I am selling or providing customer service for, after sales service or anything, I try to make sure that I have the maximum knowledge that I can get for that job. But if I, after receiving all that information, if I still feel that I'm unable to answer a question, I do a courtesy close and I let them know that as soon as I get the answer to the question, if it's to a specific problem, that I would get back to them. If it's something that I think the supervisor or the senior might know, I might just quickly ask the permission to put them on hold and if possible, contact the manager or the supervisor and get an answer while on the call. If I know that the supervisor won't be able to answer quickly, I would do a courtesy close, apologize and let them know that as soon as I fix the problem or whatever conclusion they're looking for, I would let them know and after I've done the research, I have found the answer, I would get back to them.