A shallow cup you fill with spermicidal cream or jelly and insert up to six hours before sex.

HOW IT WORKS Prevents sperm from entering the uterus.

PROTECTION 24 hours.

BABY-PROOFING ABILITIES 90 percent.

STD-PROTECTION Some protection against PID, chlamydia, gonorrhea and trichomoniasis. It reduces risk of cervical cancer.

SIDE EFFECTS YOU NEED TO KNOW ABOUT It's been associated with urinary tract infections.

CAN IT RUIN THE MOMENT? It can be inserted up to six hours before sex, but you have to add more cream/jelly each and every time he ejaculates (which in itself can be pretty sticky, messy stuff).

HASSLE FACTOR Medium. It takes practice to put in. Then you have to refuel after use, regularly check for holes and get it refitted if you gain/lose a lot of weight. Also, it must be left in place six hours after ejaculation.

PLEASURE BAROMETER Some women say the rim stimulates their cervix.

BAD HABIT PENALTIES Using any oily products (like Vaseline, baby oil and massage oils) are a no-no since they can make your rubber cup leaky. Not adding more spermicide reduces its protection.

OPERATING INSTRUCTIONS Before inserting, check for holes or tears by holding it up to the light. Then spread spermicidal jelly or cream on the inside portion of the dome and rim with clean, washed hands. Put the diaphragm all the way back against the cervix with the cavity containing the spermicide covering the cervical opening; feel around the edge to be sure the cervix is completely covered. If you have sex more than an hour after inserting a diaphragm, or if you have sex more than once in one night, you'll need to squirt some more spermicide into your vagina (don't remove the diaphragm). Leave it in place for at least six hours after his last ejaculation, but no more than 24 hours. Remove it by sticking your fingers into your vagina and gently grasping the rim and pulling. Then wash it with soap and water, dry it, and store it in a cool, dry, dark place.