For some of the connector series', the top-entry surface mount headers require a suction cap for pick-n-place equipment vacuum nozzles. As such, those for which it applies would have an extra "T" suffix to the part number. For example, to have part number BM06B-SRSS-TB include the suction cap, it would be ordered as BM06B-SRSS-TBT. The same would apply to most top-entry headers with a "-TF" suffix. The SHD series is the exception whereas it uses a hard plastic cap thereby the suffix would be "-TFC".