What can i send my marine in afghanistan for his birthday?

my boyfriend left to afghanistan about a month ago and wont be back till the end of the year ): he will be turning 21 over there in two months, the only problems is tht I have no idea wht to send him!! Please help!! I already decided on "cake in a jar" a personalized birthday card, and a photo of me....... but I don't have an actual gift, those are just a few small things. Please help ):