This is the O.S. Engines OCA-240 40A 25V Electronic Speed Control with OCP-2 Programming Card. Features: Low voltage cut-off stops motor before control is lost and cells are over-dischargedStart protection guards against involuntary starting of motorFor airplane and helicopter useBattery type and cell number recognitionNo signal cut-off switches ESC off when transmitter signal is not received Includes: One O.S. Engines OCA-240 40A 25V Electronic Speed Control with Motor and Battery Leads, Receiver Connector and Instructions Requires: Brushless motor such as the O.S. OMA-2810-1250, OMA-2815-1100, OMA-2820-950, OMA-3805-1200, OMA-3810-1050, OMA-3815-1000 Battery connectors of modeler"s choice (O.S. motors listed above include ESC connectors)