700x45 Black/Tan Riddler TCS Light Fast Rolling Bicycle Tire Razor Drift Rider This is the replacement rear

This is the replacement rear transport chair caster wheel for the Drive Duet rollator/transport chair or D-Lite rollator (750N)

and sports a nice black finish

Panaracer: RF728-RCA-B4

The caster comes with pre-installed 608ZZ bearings

then this is the one you are looking for

700x45 Black/Tan Riddler TCS Light Fast Rolling Bicycle Tire Razor Drift Rider This is the replacement rearLarge, supported toothy side knobs and densely packed, low centered tread. The Riddler is a fast rolling tire with great cornering abilities named after WTB athlete Nathan Riddle. XC AM tire designed for use on dry to damp and hardpack to sand trail conditions. Light Lighter weight compound conforms to trail objects while still providing a happy balance between low rotational weight and reliability. FR Fast Rolling, with WTB's Dual DNA rubber compound