Thimble-shaped rubber cap you fill with spermicide and fit over cervix.

HOW IT WORKS Prevents sperm from entering uterus.

PROTECTION 48 hours.

BABY-PROOFING ABILITIES 84 percent.

STD PROTECTION Some protection against pelvic inflammatory disease (PID).

SIDE EFFECTS YOU NEED TO KNOW ABOUT May dislodge during vigorous intercourse; it can't be used during your period.

DOES IT RUIN THE MOMENT? No. It can be inserted up to six hours before sex and stay in place for up to 24 hours.

HASSLE FACTOR Medium. Insertion can be a little awkward and the cap must be kept in place at least six hours after intercourse.

PLEASURE BAROMETER None.

BAD HABIT PENALTIES Using any oils, since they can cause holes in the rubber.

OPERATING INSTRUCTIONS Before inserting, check for holes or tears by holding it up to the light. Fill one-third to one-half of cap with spermicidal jelly or cream. Insert by squeezing the cap between thumb and index finger, sliding it into your vagina and pressing rim around cervix (feel around the edge to be sure the cervix is completely covered). To remove, press on the rim until the seal on cervix is broken, tilt cap, then hook fingers under the rim and pull sideways out of vagina. After use, wash with mild soap and water, and dry thoroughly; store in a cool, dry, dark place.