Excelitas Technologies will add to its 160 employees as part of a multi-million dollar expansion that will get a 15-year Miamisburg tax abatement and a $175,000 Montgomery County Economic Development/Government Equity grant, records show. The Mound Development Corp. is guaranteeing an investment of more than $6.5 million for a 30,000 square foot building addition at 1100 Vanguard Drive, said Mound Development Corporation President Eric Cluxton. “This is a big deal,” Cluxton said of the package approved by Miamisburg City Council on Tuesday night. “This isn’t manufacturing (jobs). This is executive office level positions.