Schluter's 10 in. x 5 in. notched KERDI-TROWEL has an aluminum alloy mounting riveted to a hard tempered steel blade that is flexible yet durable. A curved rubber handle, is designed to lessen user fatigue. It also features square -shaped notches (1/8 in. x 1/8 in. x 1/8 in.), which easily spread large quantities of mortar or adhesive.