Very thin aluminium, welds not very strong (one has already snapped), won't hold up on its own, not to mention full of junk and uses steps regularly. Attaches with steel brackets inside and out with 10 5/8" screws. I wish I'd spent more on a better box or just made my own.
Houseables Reflective Reflector Visibility Adhesive
9 Review
ποΈ 4 Pack of Chris Products CH4R Red Mini License Plate Reflectors for Motorcycles
9 Review
π Safe Way Traction 2" x 12' Roll 3M 983 Series Diamond Grade Conspicuity Trailer DOT-C2 Reflective Safety Tape Red & White 6β/ 6β Pattern 983-326: Enhance Trailer Safety with High-Visibility Reflective Tape
9 Review
Pirelli Scorpion Verde All Season 235/60 R18 103H
49 Review