Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Light could be brighter.

Models: KN-COSM-IB and i12080. Easy to install and replace. In my state, combination CO and Smoke units must have Voice warnings. The i12080 unit with the light is a nice feature, though could be a bit brighter.I have multiple of both units installed on the "interconnect network" of 110V power. The interesting thing discovered is when pressed the Test button on the i12080, only the other i12080 on the entire interconnect network would sound the alarm test and light up. The KN-COSM-IB stays silent. When pressed the Test button of the KN-COSM-IB, all units on the network would sound the alarm and light up.Weird. Let's see how long the backup 9V battery lasts in these units. Other users have reported horrible experiences.