Balustrades of metal; bars for metal railings; door handles of metal; knobs of metal; sash lifts of metal; pipes of metal; covers for pipes of metal; spring-shaped metal knobs with non-slip function; cover for spring-shaped metal knobs with non-slip function; cover for spring-shaped metal pipe with non-slip function; non-slip covers for metal handrails in the form of a spring for use in shower rooms; metal non-slip handrails in the form of a spring for use in shower rooms; non-slip covers for...