Hi, thanks for the offer letter. I have one concern about the timeframe. You mentioned that this offer explodes in 48 hours. I'm afraid this doesn't work at all for me. I'm currently wrapping up my interview process at a few other companies, which is likely to take me another week or so. So I'm going to need more time to make an informed decision.
The next company I join will be a big life decision for me, and I take my commitments very seriously. I also need to consult with my family/friend/mentor. There's no way that I can make a decision I'm comfortable with in this short amount of time.
Please allow me two weeks from today's date to accept the offer.