Our recommended corner putty knife for smoothing HYDROBLOK joint sealant on all interior seams. Made of durable, lightweight polypropylene plastic for easy clean-up and removal of cured HYDROBLOK joint sealant. Each HYDROBLOK Shower Pan includes a straight and a corner putty knife. Also available separately from all HYDROBLOK dealers. – Designed for installing the HYDROBLOK Shower System – Disposable – Durable ABS Plastic