(CNN) -- "Stop worrying while your baby sleeps!" reads the box on one model of the Angelcare Movement Sensor with Sound Monitor.
"The peace of mind you need," says the box containing another model.
But news announced this week by federal authorities working with the company was far from reassuring.
Citing two deaths by cord strangulation, the U.S. Consumer Product Safety Commission said Thursday that the company is recalling 600,000 Angelcare Movement and Sound Monitors with Sensor Pads.
"The cord attached to the baby monitor's sensor pad is placed under the crib mattress, which poses a strangulation risk if the child pulls the cord into the crib and it becomes wrapped around the neck," the safety commission said Thursday in announcing the voluntary recall.
In one case, a 13-month-old girl died in San Diego in November 2011; in the other case, an 8-month-old girl died in Salem, Oregon, in August 2004.
"In both fatalities, the cord from the sensor pads was pulled into the crib by the infant," the CPSC said in the announcement posted on its website.
In two cases that did not prove fatal, two infants were reported to have become entangled in the cords. The report did not elaborate.
The monitors -- made by Angelcare Monitors Inc., of Quebec, Canada -- include a sensor placed in the crib under the mattress to monitor the baby's movement. On all models that did not include rigid cord covers, the sensor pad is connected to the monitor unit by an approximately 11-foot electrical cord, which "can be pulled into the crib and can wrap around the child's neck."
The recall covers all versions of Angelcare sensor monitors that did not come with the rigid cord covers, including numbers: AC1100, AC201, AC300, AC401 and 49255. The model numbers are located on the back of the nursery monitor unit. They were made between 1999 and 2013.
The company is offering a repair kit that includes rigid protective cord covers, a new, permanent warning label and revised instructions.
The monitors cost $100 to $300 and were sold between October 1999 and September 2013 at Babies R Us/Toys R Us, Burlington Coat Factory, Meijer, Sears, Walmart, Amazon.com, Target.com, Overstock.com, and almost 70 small baby-specialty stores.
"Consumers should immediately make sure cords are placed out of reach of the child and contact Angelcare toll-free at (855)355-2643 between 8 a.m. and 8 p.m. ET Monday through Friday or visit the firm's website at www.angelcarebaby.com to order the free repair kit," the announcement said.
Early Friday, a call to that number elicited a recording that said its voice mail was full. The company did not immediately respond to an e-mail.
The CPSC announced in 2011 that there had been seven reports of strangulation by baby monitor cords since 2002. Since then, the number of deaths has risen to eight.
On Friday, eBay was offering 195 Angelcare monitors from as little as $0.99 to $260.00.
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