Shower Door thresholds are mounted directly below the shower door to let the water drain back into the shower stall. Ideal for flat or out-sloping curbs. The rounded low contour of the Half Round, Threshold will not harm feet. The Tapered Style sill leaves a minimal sight line from the exterior of the shower. Thresholds may be used in conjunction with a bottom sweep. Use Mildew Resistant Silicone sealant to adhere to curb of the shower stall.