The Tolsen 55163 is a privacy tubular knob lock designed for interior doors, providing a simple and reliable way to secure private spaces like bathrooms or bedrooms. It features a 51mm diameter knob crafted from stainless steel with a satin finish, which is protected by a wear-resistant multi-layer coating to keep it looking fresh over time. The assembly is completed by a 65mm iron rose and a durable brass cylinder that ensures smooth rotational operation. This lock is built to fit a wide range of standard doors, accommodating thicknesses between 35mm and 45mm. Its adjustable backset of 60-70mm allows for flexible installation across different door frames, making it a practical choice for homeowners or builders looking for a sturdy, functional hardware solution that blends into a modern interior.