Use Shocka Mats to protect plants in pots / plants in borders from slugs and snails. Stand your pots and containers on these simple, but effective Shocka Mats to protect them from snails and slugs - make sure there is at least 2cm overlap. Or place around plants in borders - these mats are pre-slit in he centre, so they can easily be slipped around plants once in position. These Shocka Mats are made from a fabric impregnated with copper, which slugs and snails HATE. Slugs and snails HATE the copper contained in this versatile mat, because of a reaction between their mucus and the copper. Shocka Mats come in packs of 10 and each mat measures 29.5cm in diameter.