Specification Overview
The document provides specifications for a series of DC gear motors, specifically model D122F with a size of 12mm. Key parameters include the number of stages, gear ratios, and gearbox length. The gear ratios are provided for different stages: 3, 4, and 5, with ratios of 10, 50, and 210 respectively. The gearbox length is specified as 9.0 mm.

Model Specifications
Four models are detailed with varying voltage, speed, current, torque, and output characteristics:

• D122-003210: Voltage: 3.0V, No-load speed: 35 rpm, Maximum efficiency speed: 27 rpm, Torque: 0.25 kg.cm, Stall torque: 1.2 kg.cm.
• D122-001100: Voltage: 3.0V, No-load speed: 110 rpm, Maximum efficiency speed: 91 rpm, Torque: 0.14 kg.cm, Stall torque: 1.0 kg.cm.
• D122-001050: Voltage: 2.4V, No-load speed: 300 rpm, Maximum efficiency speed: 240 rpm, Torque: 0.07 kg.cm, Stall torque: 0.4 kg.cm.
• D122-004298: Voltage: 3.0V, No-load speed: 50 rpm, Maximum efficiency speed: 40 rpm, Torque: 0.4 kg.cm, Stall torque: 2.2 kg.cm.

Applications
The motors are suitable for use in electronic locks, optic equipment, and medical apparatus. Complementary products include customized shafts, additional lead wires for motors, and specially designed motors.

Mechanical Dimensions
The document includes a picture of the DC gear motor D122F, emphasizing its compact size of 12mm.