Waterstop-RX is a hydrophilic strip waterstop designed to stop water infiltration through cast-in-place concrete construction joints by expanding upon contact with water to form a positive Seal against the concrete. Waterstop-RX 102 is produced in a half-circle (Crescent) shape. RX-102 is designed for vertical concrete and horizontal concrete. RX-102 should be used in concrete with one row of steel reinforcement, concrete curbs, planter walls, fountains, and lightweight structural concrete.