The Newton Fire Department’s latest tool is about the size of a cell phone and fits perfectly in the palm of Fire Marshal Mike Knoll’s hand. Despite its small proportions, the newly donated air monitoring device will help Newton’s firefighters conduct their jobs more safely and potentially save lives. The device — called an MSA Altair 4X Multigas Detector — is an upgrade from the department’s previous model, which looks more like an oversized pager by comparison. Holding both devices in his hands and inspecting the size differences, Knoll just shook his head and smiled: “That’s technology.”