"They either stick together, almost too firmly to separate, or they repel one another, depending on which way they’re facing. So you’ll use this." He indicated a rectangle of stiff black plastic, covered with silver tape. A length of olive paracord was looped through two holes, at one end. "Soft plastic envelopes under the tape, one for each disk. You carry it in down the front of your jeans, then hang it around your neck for climbing. Slip them out one at a time as you cover the nine holes. They should cover any spalling completely, as well as sealing the hole."