Color: a. Black Suitcase Carry-on S size with expansion function, brake casters, TSA lock, 40L, carry case, business trip, travel, 1-3 nights [Expansion function for flights, 3-stage adjustable caliber] Designed for in-flight travel, business trips, and travel, it features an expansion structure with a zipper closure. By expanding the gusset width by about 5cm, the capacity increases by about 20%, so you can rest assured even if your luggage or souvenirs increase during your trip. The lightweight and durable aluminum alloy caliber can be adjusted in 3 stages to suit your height and usage scenario with a one-push operation. [Dry and wet separation storage, hanging storage, dust cover included] Equipped with a dry and wet separation bag that allows you to store wet and dry items separately. Inside, there are convenient pockets for temporarily storing small items, smartphones, documents, tickets, etc. A dust cover with dustproof specifications is included, which can be folded and stored when not in use. [Removable, double casters with brakes] Durable double-wheel casters are used, providing smooth 360-degree rotation for comfortable travel. The design suppresses vibrations and noise during travel, allowing for stable movement even on uneven surfaces. With the brake function, you can travel with peace of mind on trains and slopes. The casters are removable, making cleaning, storage, and replacement easy. [Highly durable hard body & YKK zipper] A hard-type body that combines ABS resin and PC (polycarbonate) resin is used, achieving both lightness and impact resistance. The main zipper uses a reliable YKK zipper, providing a long-lasting and stable feel. [TSA dial lock equipped] Equipped with a TSA dial lock for peace of mind when traveling abroad. Airport inspections are possible while locked.