Emerald Alarms EP-HYB-240-10

Awful product, poorly thought out, just like the smoke alarm standard. One falsing smoke alarm sets off the whole house and can't be reset or turned off quickly. Falsing units will need to be taken down, snip the speaker wires and pop the RF unit out to stop the others going off. This product and set of standrds single handedly defeats the purpose of smoke detection. When the alarm goes off, instead of evacuating, you set out to find the falsing unit. Alarm duress and hard-wiring introduces an injury and electrical risk to those attempting to remedy the problem.

For the love of God don't hard wire them! Smoke alarm standards do not require 240v supply, just interconnection. You will need to replace the unit in 10 years anyway due to expiration of the UNREMOVEABLE battery as it is the secondary power source required by the standard.