Every case in this set carries a secure 3-digit combination lock, which is the feature most three-piece sets leave to an add-on padlock that then gets cut off in transit. Set your own code once and the shell stays closed through handling, and there is no key to lose halfway through a trip. The set covers three trip lengths on real numbers rather than nominal inches. The 20-in case measures 13 in by 8.5 in by 22.5 in, holds 42 L at 5.5 lbs, and is rated airline standard carry-on for 1 to 4 day trips. The 24-in case measures 15.5 in by 9.5 in by 27 in, holds 69 L at 6.5 lbs, and goes as checked baggage for 4 to 7 days. The 28-in case measures 20 in by 12 in by 30.5 in, holds 99 L at 8 lbs, and covers 7 to 9 days as checked baggage. All three are built in ABS with a robust hardshell that is scratch-resistant and impact-resistant so the finish survives a baggage belt, and each rides on 360 degree double spinner wheels that stay silent, smooth, reliable, and flexible when the case is loaded. A sturdy adjustable telescoping handle sets towing height and reinforced grab handles make lifting more comfortable, while multiple inner compartments keep belongings tidy and accessible behind smooth zippers. Nothing needs assembling. The set arrives ready to use, and between trips the nesting design stacks the smaller cases inside the larger so all 20 lbs of luggage stores in about the footprint of one case.