I'm wanting to buy a Bosch ISM-BLD1-P burglar alarm sensor, to replace a

non-pet friendly sensor that is currently installed- it is a pain to keep

pets out of that particular room. (The rest of the house is covered by

existing ISM-BLD1-P's).

The webpage mentions that there are different microwave frequencies that the

detector can operate at, with each different frequency variant having a

different letter at the end of the product code (F1, F3 or F4).

Are you able to advise which frequency I am likely to require- are these

different units? I can't find any mention of microwave frequency in any of

the documentation for my current system.

On these units the freq is set per country. You can't get the different freq in the UK. There is only one.