Silicon Progrmmable Unijunction Transistor (PUT), TO-92 case. 

Replaces 1855-0314, 188304, 2007200000, 21-1AA, 21-1AA(MAGNAVOX), 2179-001-1302, 23115903, 26999-16, 28723-09, 2N6027, 2N6028, 305-009001, 305-009002, 309444, 3165, 3438869, 3597379, 3656465, 3755931, 3L4-7004-1, 417-823, 417-823(P.U.T.), 46-86571-3, 48-137638, 48S137638, 48S155275, 48S455275, 48T43738P01, 561-6806-027, 561-6806-028, 610121-1, 610121-1(PUT), 610121-2, 610121-2(PUT), 610121-3, 6631000200, 6631001200, 66F1301, 707W00084, 72131-001, 72131-002, 72131-102, 723-09, 744070, 8000-00042-014, 801535, 801551, 86-572-2, 86-572-3, 86-668-9, 86X0070-001, 8-729-101-13, 8-729-101-31, 991-015316, 991-015316-000, 999-16, A1-TSU-NOO-002, A7T6027, A7T6028, AR410, CXL6402, D13K1, D13T1, D13T2, DDFY017001, ECG6402, GE-X17, HEP-S9001, HEPS9001, MPU131, MPU6027, MPU6028, N13T, N13T1, N13T2, NTE6402, P13T1, PTN1