Philips Norelco BT5215/41 Beard & Head trimmer Series 5100, Black, 0.0157" (0.4 mm), 0.512" (1.3 cm), Stainless steel, AC/Battery, 70 min Philips Norelco BT5215/41 Beard & Head trimmer Series 5100. Product color: Black, Minimum hair length: 0.0157" (0.4 mm), Maximum hair length: 0.512" (1.3 cm). Power source: AC/Battery, Operating time: 70 min, Battery type: Built-in battery. Cutter material: Stainless steel