what's different between PS561SD and PS561

[nybuck]

The motion sensors are battery powered, so they would probably work   

They send the signal via RF, and different countries use different bands   

It might work, but he already said he couldn't return them.....

Also, I wonder if the "free shipping" deal holds true overseas......  (I'm thinking not)

[Brian H]

Our 310MHz RF frequency modules will not work with overseas devices but should be fine with US designed modules.
Most of the overseas units are 433.92MHz.

Not sure if he ordered the stuff yet. As I thought he asked if giving his Credit Card Number over the phone was OK.