360 degree bumper made of steel/CFRP. Lightweight, around 100g. I bought it from local R/C store in Japan. I think it's the shop's original. I tested today. Of course, it affects front view - in 16:9 footage, it'll be in unless 10-20+ degree down camera. The followings are taken in 5 knot head wind (equiv. 10m/sec forward moving). The 12 steel wires are easy to attach/detach. Once attached 4 arms using screw driver (each 2 motor fixing screws), can be fold without screw driver - however it extents about 1cm, and it's hard to put into my bag (Vanguard up-rise 48). Without wires, the arms itself will be instant guard, I think. . Today I didn't crash so I don't know about its strength, but seems very tight.