Eatelle 1/2" Wide X 1/4" Clear Acrylic Frameless Shower Dam / Threshold 36 Inch Use 100% pure clear silicone chalk. After you figure out the correct length and position for the threshold place a strip of masking tape on both edges. This way when the chalk oozes out from under the strip it goes on the tape. After it dries pull off the tape and you have a super clean edge. Also Very Hi-Bond Acrylic Adhesive Tape would work. Transparent semi-circular rod, perfect as a splash protection profile and water repellent Suitable for all glass showers Can be cut to size The strip is glued to the floor, not to the door(adhesive NOT included)