Rubi Steel Notched Trowel - 3/16" x 3/16" - Install Schluter Ditra underlayment Great for installing Schluter DITRA Notches Size: 3/16 x 3/16 (4.5 x 4.5 mm) Jagged Trowel with Open Rubiflex Handle With a highly adherent rubiflex handle Plates highly resistant to wear