Package Content: The package comes with 4 pieces 3-in-1 portable door locks; It is the warm and practical gift choice for friends, girlfriend, moms, classmates, colleagues, relatives, students, etc. precision casting made of quality 304 stainless steel, strong and can serve you for a long time; It is very reliable, unable to open the door even if it is pushed hard, providing you with additional security, protection and privacySimple to install: you can easily install the door lock without any installation tools, even if someone outside the room has the key, it is difficult to open the door lock; The additional locking device is specially designed for travelers, students, single mothers, suitable for families, hotels, schools, travel, etc. Size information: the travel door security lock measures about 3.15 x 1.97 inches/ 8 x 5 cm, with light weight and compact size, it is portable and can be carried in your pocket or handbag for protection. 2. the side of the door should be flat