Audio Technology Active Noise Cancellation Transparency mode Adaptive EQ Vent system for pressure equalisation Custom high-excursion Apple driver Custom high dynamic range amplifier Spatial audio with dynamic head tracking1 Sensors Dual beamforming microphones Inward-facing microphone Dual optical sensors Motion-detecting accelerometer Speech-detecting accelerometer Force sensor Chip H1-based System in Package Controls Press once to play, pause or answer a phone call Press twice to skip forwards Press three times to skip backwards Press and hold to switch between Active Noise Cancellation and Transparency mode Say “Hey Siri” to do things like play a song, make a call or get directions Sweat and Water Resistant2 Sweat and water resistant (IPX4) Size and Weight (Each)3 21.8 mm (0.86 inches) 30.9 mm (1.22 inches) Height: 30.9 mm (1.22 inches) Width: 21.8 mm (0.86 inches) Depth: 24.0 mm (0.94 inches) Weight: 5.4 grams (0.19 ounces) 60.6 mm (2.39 inches) 45.2 mm (1.78 inches) 21.7 mm (0.85 inches) Height: 45.2 mm (1.78 inches) Width: 60.6 mm (2.39 inches) Depth: 21.7 mm (0.85 inches) Weight: 45.6 grams (1.61 ounces)