The CST E-Series Reach features a robust casing with thick fast rolling tread pattern and comes equipped with APL and a reflective sidewall for increased night visibility. APL - Anti-Puncture Layer features a respectable 0.7mm layer of rubber between the tread and the casing. REF - Reflective sidewall striping or hotpatch to aid in low light visibility. E - designated tires are designed to specifically withstand use on E-Bikes with an upgraded casing and bead