Secure entry/front door lock: Crafted from stainless steel and copper for strength and durability, this lock provides key access from outside and a rotary knob inside, delivering smooth operation and reliable security for your main entrance. Versatile use for bedrooms, offices, and hotels: Suitable for door widths from 30–50 mm, offering practical security solutions wherever you need privacy and controlled access. Simple installation with key: Quick setup without complex steps. Fit it yourself with basic tools and start using immediately for enhanced convenience. Enhanced protection with a thickened solid lock: Features a robust singlesided locking mechanism to deter unauthorized entry, providing peace of mind day and night without compromising ease of use. Use scenarios: Main entry door at home or small business: exterior key access with an interior rotary knob for reliable daily operation. Private offices or hotel guest rooms: protects privacy while allowing authorized access with a key from outside. Bedroom or interior doors requiring privacy with controlled access on doors 30–50 mm thick.