This is the Great Planes ElectriFly 3.5mm male bullet to 2mm female bullet adapter.
Features: Connects a motor with 2mm Male Bullet Connectors to an Electronic Speed Control with 3.5mm Female Bullet Connectors
Includes: Three Great Planes ElectriFly 3.5mm Male Bullet to 2mm Female Bullet Adapters
Connector #1: 3.5mm Male Bullet
Connector #2: 2mm Female Bullet
Weight: .05oz (1.41g) each adapter