I remember buying these as a matched set, but I have the matching red striped version of each.

Seat Pad: https://www.amazon.com/dp/B01NAB5V3G/ref=cm_sw_r_apan_i_QMD2QW4WP0VDAZ2CF15P?_encoding=UTF8&psc=1

Back Protector: https://www.amazon.com/dp/B01MQODEUN/ref=cm_sw_r_apan_i_SF894ZZH7BYPNS4EBYRM?psc=1