The Stanford Research SR255 Fast Sampler module is a gated integrator with four discrete, user-selected gate widths from 100 ps to 1 ns. All of the necessary electronics are built into this high-speed module including an A/D, D/A and a PROM correction circuit to eliminate the inherent non-linearities in the sampling bridge. The SR255 is perfect for fast pulsed experiments where the 2 ns minimum gate width of the SR250 is insufficient. The gate delay is controlled by a rear-panel voltage input which can be supplied by the SR200 Gate Scanner or the SR245 Computer Interface. Convenient gate view and signal outputs allow precise positioning of the gateToneparticularly important in applications such as time domain reflectometry or shorted-cable baseline subtraction. The SR255 can be used alone, combined with the SR245 Computer Interface module for automated data acquisition, or operated with the SR200 Gate Scanner for scanning gate waveform recovery.