Rubber. Jimmy-hat. Love sock. Wrapper. However you say it, male condoms are one of the most popular forms of buyirth control out there. They slip over a guy's penis to prevent pregnancy and lower the risk of STIs by keeping the guy's sperm inside the condom and out of your vagina.
They protect against STIs, don't require a prescription, and are inexpensive. Win! They also need to be used every time in order to be effective.
Effectiveness - http://glw.io/hlXkS