SMPL's door sensor sends its alert to a portable monitor that rings, vibrates and flashes, so the signal follows the person who answers from room to room.

• Reaches about 150 feet indoors on its own local radio link.
• Pairs up to 20 sensors with one receiver as the house needs more.
• Plays a different tune for each sensor, so the bedroom door and the exit sound distinct.
• Runs with zero Wi-Fi and zero monthly fees.

Picture a daughter cooking dinner while her father rests in the den. When the back door opens, the monitor on the counter buzzes beside her before she hears the latch.

Setup takes minutes with the pre-applied tape, and placement decides how well it works.

The SMPL manual asks for the sensor and magnet to sit less than half an inch apart with the door closed. Metal can weaken the signal, so test a metal frame before pressing the tape down.

This two-piece exit sensor alerts a caregiver pager the moment a door or window opens. Smart Caregiver designs it for the inside of the house.

• Covers bedroom doors, exits, sliding glass doors and windows.
• Alerts by sound or vibration, so a light sleeper can choose a quiet buzz by the bed.
• Links up to six sensors per pager, so the kit grows with the house.

It fits the spouse who sleeps lightly in the next room and wants a quiet buzz by the bed when the front door opens.

Start with the exit your loved one tries most often, then add a second sensor to the bedroom door if nighttime walking begins there.

Every person who opens the monitored door triggers the pager, including visiting relatives and aides. Agree on who resets it and where the pager lives at night, then carry it through the basement and yard to test the signal.

Vive's LVA2063DOR pairs a slim adhesive door sensor with a wireless pager that runs on two AA batteries. The sensor stays silent and the pager does the alerting.

• Signals with a chime and vibration, plus a number showing which door or window fired.
• Reaches up to 150 feet in an open field.
• Pairs with ten devices and clips to a belt, so it moves with you.
• Clears an alert with one large stop button on the pager face.
• Lasts about 24 months per sensor, with an indicator when it needs replacing.

That big button helps at 2 a.m., when a caregiver wants quiet fast and the person at the door is already confused. One pager can cover the front door, back door and a window.

Built for indoor doors and windows, it loses range through walls and floors, so test the pager upstairs with the bedroom door closed before the first night.

The TL-4005HOME system watches for a wristband, so the alert depends on who approaches the door. When your loved one nears the door bar wearing the resident band, the pager warns with light and sound.

• Stays quiet for everyday comings and goings by the rest of the household.
• Sends a visual and audible warning to a wireless pager you carry.
• Resets from a wireless reset button after each alert.
• Runs the door bar on an AC adapter near the door.

That matters in a busy home: a grandson heading to school, an aide arriving, a neighbor dropping off groceries.

The pager travels around the house and yard, so the caregiver can garden or fold laundry in the basement while the front door stays covered.

The system fits standard-size doors, and the alert depends on the wristband staying on, so plan how it goes back on after bathing and who checks it each morning.

This CallToU kit pairs two door sensors with a plug-in receiver that sounds and lights up at home. The phone app sends the same alert to every phone you share it with.

• Covers a 500-foot range, per CallToU's listing.
• Expands with more sensors or receivers for a second exit or a bedroom.
• Pairs sensors when the triangle marks on each half face each other during setup.
• Connects to 2.4 GHz Wi-Fi networks only, so check the router first.

It suits a split arrangement: Mom lives with a husband who hears the receiver, while a daughter across town gets the phone notification and calls to check.

Decide in advance who walks to the door when the alert arrives, because a phone notification travels farther than any helper.

CallToU has listed the kit out of stock, so confirm availability before planning around it. Keep the receiver where someone at home will hear it at night.

YoLink's starter kit pairs a hub with door sensors and sends open and closed alerts to the YoLink phone app, which suits families watching more than one exit.

• Ships the base kit with one hub and two sensors.
• Adds more sensors on the same hub in the four-sensor kit.
• Offers a SpeakerHub version for spoken alerts inside the home.
• Sends remote notifications once the hub is plugged in near the router and online.

Think of a son who lives two hours away and wants to know when the back door opens after dark, while his mother's neighbor checks in nearby.

Phone alerts inform family, and a local responder walks to the door, so name that neighbor before the first night.

Match the kit size to the exits you plan to monitor. Then open each door while someone watches the phone, and note how many seconds each alert takes to arrive.

UltraPro's model 45115 two-pack puts a battery alarm right on the door or window, and it sounds when the magnet separates from the base.

• Switches between a gentle chime, off and a 120-decibel alarm.
• Mounts with the included double-sided tape and zero tools.
• Comes with four LR44 batteries and an LED low-battery light.
• Costs under $20 for two, a low-cost second layer.

It works best as a second layer where someone is close enough to hear it, such as a basement door off the kitchen or a sliding door by the family room.

The sound stays at the doorway, so a caregiver down the hall may miss it, and a sudden siren can startle the person opening the door.

Try the chime setting first and walk to the bedroom to check whether you can hear it. Jasco's image shows GE-branded packaging, so confirm the exact version and loudness rating at checkout.