Feature: 1. USB CHARGING: DLP LinK 3D glasses are USB charging type, just a data cable can give it a full charge, very convenient and fast. 2. LONG LIFE TIME: 3D active shutter glasses built in lithium rechargeable battery, charging 2‑3 hours can last about 30‑45 hours, long life time. 3. COMPATIBLE: 3D glasses 3D effect shocking, compatible with 96‑144Hz, support the major brands of DLP LINK technology 3D projector (regardless of brand). 4. LEFT AND RIGHT EYE SWITCHING: DLP 3D glasses support one button left and right eye switching, easy adjustment, high light transmission rate. 5. SMALL AND LIGHTWEIGHT: USB 3D glasses are small and light, so they are not too heavy when used and easy to store and carry when not worn. Specification: Item Type: 3D Glasses Material: Plastic, Electronics Operating Mode: LCD Shutter Frequency: 96‑144Hz Transmittance: 36% (TYP) Contrast Ratio: 1000:1 Standby Time: 180 Days Charging Time: 2.5 Hours Continuous Working Time: 45 Hours Signal Reception Distance: Approx. 8m/26.2ft Battery Type: Built in 45mAh Lithium Battery (included). Package List: 1 x 3D Glasses1 x Glass Cleaning Cloth1 x Charging Cable1 x Instruction Manual Note: All data are measured manually, and there are certain errors in the measurement results.