Uniden DECT3105 Additional Handset. Designed and engineered in Japan, Uniden's DECT 31xx Series uses the Wireless Friendly DECT technology. This Additional Handset has been derived from cutting-edge American DECT 6.0 Technology the DECT 31xx Cordless Phone System is nothing but a premium choice. We've introduced a handy NEW feature to the DECT 3105 - Blackout Power Failure Protection Feature. When a Power Failure occurs, the charged handset temporarily supplies power to the base unit. You can then make and receives calls using a handset.