Features: 1) Voice alternative by pushing "UP" and "DOWN" button to change voice levels (8 different masking levels) 2) Volume level adjustable with power on / off switch 3) Mini handheld design 4) Convenient for carrying 5) Easy operation (simply tap it to the mouth piece of the telephone handset and tune on the power) 6) Call screen: bypasses answering undesired phone calls and reduces harassment calls 7) Visitor screen: filters visitors through indoor intercom and refuses undesired visitors by changing to different person 8) Size: 89 x 60 x 23mm 9) Weight: 130g 10) Single female can refuse unwanted dates or solicitation 11) Children who are left at home alone can ward off villains 12) Wives can spy on their husbands 13) Husbands can investigate their wives 14) People entertains friends and family members Certification(s): CE, FDA, RoHSSupply Ability: 20,000pcs