The attachments included: 10mm Flat spacer for quick release rear wheel.(Use it when your bicycle's drop out is not flat enough for installing a hitch.)
between QR skewer handle to the end cap will increase about 5mm, most stocked skewer is not long enough for the extra 5mm. In this case, the skewer and cap's matched thread will be decrease significantly, that may cause the skewer can't holder the wheel tight enough.
Why you need a titanium alloy Skewer: When the skewer's job is only holding the wheel and keep it on the bike alll forces are acting in the direction of the QR axle shaft, but when towing a trailer, unpredictable torsional force is transmitted to the end of the QR skewer, it may cause bending at the skewer' end and even damage the bicycle frame.
Description
Performance advantages of titanium alloy compare to steel materials: Higher strength, lighter weight, better corrosion resistance, and better elasticity