This 40 pack of MACH-2™ is the deluxe and stylish, robust and versatile Multimedia USB Headset from HamiltonBuhl®that will connect to any device with a USB port, whether Chromebook, PC or Mac! Featuring high quality integrated USB sound, noise-canceling steel-reinforced gooseneck microphone with on-ear cup volume control dial, soft leatherette ear cushions delivering excellent noise-isolation, and adjustable, folding headband, MACH-2™ is designed for all-day comfort and easy compact storage. With the exclusive Dura-Cord™ (chew, kink and knot-resistant, PVC-jacketed, braided cord), and an Anti-Lice storage bag (heavy-duty, write-on, moisture-resistant, reclosable bag that kills lice within 24-48 hours), MACH-2™ Multimedia USB Headset is loaded with sought-after features. The ideal companion for ever-growing and changing technology in the classrooms, this deluxe, over-ear multimedia USB headset is the high quality, durable yet comfortable accessory each student needs to get the most out of their high tech lessons." "Headset Specifications: Foldable Leatherette Padded Headband Noise-isolating Leatherette Ear Cushions 40mm Speaker Driver Ear Cup Volume Control Frequency Response: 50-20,000 Hz Impedance: 32Ω Anti-Lice Storage Bag: Heavy-duty, write-on, moisture-resistant, reclosable bag. Helps prevent the spread of lice! When sealed in the bag, lice are killed in 24-48 hours without the use of chemicals 5' Dura-Cord™ – chew-resistant, PVC-sleeved, braided cord USB Plug for Stereo Audio and Mic Prop 65 Compliant Microphone Specifications: Omnidirectional Passive noise cancelling microphone Steel reinforced gooseneck mic Sensitivity: -36±3DB Frequency response: 50Hz-16Khz Impedance: 2.200Ω"