Get two 3-way switches and substitute them. You'd need to show where the power comes from and what's between the switches to know if it would work with what you have. You may not have enough wires, and then again, you might! Depends on how it is currently run. Functionally, if you ganged the two handles on each device together, and wired it properly, you might make this work, but that's what a 3-way switch is internally, a DPST switch (unless I'm all mixed up). Looks like you're missing the traveler between the switches, but those things give me a headache and I may be missing something.