Common units have length adjusted by the user prior to use and only speed is controlled. This unit has two knobs on the controller so it might be a high-end unit with depth and speed control. Typical the mechanism for that is advertised as a linear actuator, although I don't know if that's specific enough for you.
A common safety measure is to have the toy set to max depth at the start of that the toy doesn't go deeper than the user expects/is capable of handling (many people will overestimate their capabilities when horny). I don't believe there's a torque limit to these typically beyond what the machine is capable of. Most are advertised as being able to push through clenching (for some this involuntary as the approach/have an orgasm).
Common units have length adjusted by the user prior to use and only speed is controlled. This unit has two knobs on the controller so it might be a high-end unit with depth and speed control. Typical the mechanism for that is advertised as a linear actuator, although I don't know if that's specific enough for you.
A common safety measure is to have the toy set to max depth at the start of that the toy doesn't go deeper than the user expects/is capable of handling (many people will overestimate their capabilities when horny). I don't believe there's a torque limit to these typically beyond what the machine is capable of. Most are advertised as being able to push through clenching (for some this involuntary as the approach/have an orgasm).