The VS-2KBB20R is a Vishay single-phase bridge rectifier in the 2KBB series, rated for 200 V peak reverse voltage and 1.9 A average rectified output current. That 200 V rating means it can handle the full-wave rectified output of a 140 VAC secondary winding with margin — the peak of a 140 VAC sine wave is about 198 V, so this part sits right at the edge of that application. The 1.9 A average current is the DC load it can sustain continuously; the 1.1 V forward drop at that current means about 2 W of conduction loss, which the 4-SIP through-hole package dissipates into the board copper. The reverse leakage is specified at 10 µA at 200 V — a low enough figure that it won't load down the AC line in standby circuits.
The 4-SIP (2KBB) package is a standard through-hole single-in-line footprint with four pins — two for the AC input, two for the DC output. The 2.54 mm pitch between pins matches common protoboard and PCB layouts.