Thank you Paul. I'm still a bit confused, but I did find where the 'B' is coming from, sort of...

DECLARE @string VARCHAR(100)

SELECT @string = 0x4200000012F80C4D00000003C5144E00000000650C

SELECT CONVERT(CHAR(10),@string)

The 'B' shows up no matter what I put in for the length parameter of CHAR. I still don't know what it means.