44 for OD ø44, S for Straight Tube fork. ZTTO code is for quick search, not a accurate specifications. Please refer to SHIS(Standard Headset Information System). ZS44/28.6, ZS44/30.
Aluminium alloy material, lightweight, durable and easy to install.
Easy to install and reliable to use, good replacement for your bike, make riding easier and more enjoyable.