Abstract: A pad includes: a pad body having upper and lower surfaces and formed with a plurality of spaced apart lower recesses, each of which is indented inwardly from the lower surface and each of which is defined by a recess-defining wall, the recess-defining wall having a base portion with a peripheral edge, and a surrounding portion that extends from the peripheral edge of the base portion to the lower surface; and a plurality of suction units, each of which protrudes outwardly from the base portion of the recess-defining wall of a respective one of the lower recesses.