Employing a 25-kHz carrier frequency, the surface-mount TSOP75D25 and TSOP35D25 infrared receivers fit into active 3D glasses, ensuring the glasses' LCD shutters open and close in proper synchronization. Both receive 3D synch signals from an 830- or 850-nm emitter. Other shared features include a photodiode, amplifier, automatic gain control, bandpass filter, demodulator, control IC, and a transmit distance of more than 26m. Small-quantity pricing is $1 each. VISHAY INTERTECHNOLOGY, INC., Malvern, PA. (619) 336-0860.