The TimeHarp 100 PC board from PicoQuant is a fully integrated system for time-correlated single photon counting on a PC card. The circuit allows >2 million counts per second in continuous mode and typical time resolution of 60 ps. The input triggers are programmable for various signals. The system is suited for fluorescence lifetime studies, with the company's PDL 800 as an excitation source. The device features 4096 time channels per range and sync frequency up to 100 MHz, and measures from 150 ns to 5 µs.