This hamster cage DIY outer tunnel mouth connection board, made from , is durable and practical for long time use. hamster cage refitting. Convenient to install firmly, not easy to break or fall off. Provide a area for curious critters to explore and to promote exercise and healthy habits. Features - ColorAssorted Color - Material: Plastic. - Size: About 9.50X9.50X1.20cm/3.73X3.73X0.47inch. - Note: Opening diameter: 7.5cm. - Adopts of , it is durable and practical. Hamster tunnel tube is not included. - You can install them on the cage to increase the fun of hamster activities. - It is sturdy and easy to install. Not easy to fall off. - Bright color design can attract your pet hamster to play. - You can use it to connect various and do more modeling channels. Package list: 4 x Connection Boards