USB 2.0 Series

U10
COB (Chip on Board) technology 
Dust & water resistant
U12
COB (Chip on Board) technology 
Dust & water resistant
U15
Aluminium metallic casing
Dongle hole design, easy to carry
U20
COB (Chip on Board) technology 
Dust & water resistant
U25
Slide-out USB connector
Aluminium metallic casing
U30
COB (Chip on Board) technology 
Ultra-tiny size and light weight

USB 3.1 Gen1 Series

U50
COB (Chip on Board) technology 
Dust & water resistant
U55
Aluminium metallic casing
Dongle hole design, easy to carry
U65
Slide-out USB connector
Aluminium metallic casing