Condoms generally cost more than 30 dollars a box. It is recommended that when choosing a condom, you must choose it according to the size of your external genitalia, otherwise it will be too big and easy to fall off, and too small will be very uncomfortable. Also, consider whether you have used this condom in the past and whether it will cause an allergic reaction in the female vaginal mucosa. If you have used it before and have an allergic reaction, it is recommended to switch to another condom to find out if there are still allergies. Some people are allergic to the lubricant of condoms, which can cause local itching, redness and swelling, and in serious cases, desensitization treatment should be given in the hospital, so be careful when choosing and combine it with whether you have used it before. If you are allergic to condoms, you can switch to other methods of contraception, such as an IUD.