Fits all railing shapes and sizes up to 6-inches wide. Patented rail design holds securely; self-mounting - no screws or brackets necessary. No drip drainage recycles water; contains a built-in drainage solution - two removable & cleanable trays. High quality materials ensuring long lasting product, weatherproof lifecycle. Patented anchoring mechanism for theft protection. Greenbo products provide a unique solution for growing plants or flowers in an urban environment. The patented design allows it to be placed over any shape or form of railings without the need for special adjustments or effort. No more cheap, simple window box designs. No more scratches, rust or damages. Easily decorate your railing with colorful and sophisticated planters. Greenbo"s main guidelines are based on simplicity, innovation and efficiency, while keeping safety as the prime prerequisite. Greenbo cares about green environment and act according to the "sustainability" ecological economics principles, by using high quality & recycled materials to ensure long lasting product life cycle.