barbed
blue
border
cable
closed
clouds
current
danger
details
electric
electrical
electricity
enclose
enclosure
energy
engineering
equipment
fence
focus
high
hurt
industrial
industry
isolated
keep
line
locked
metal
painful
pointy
power
prohibited
protection
rust
safe
safety
security
shallow
sharp
sky
steel
structure
surveillance
threat
voltage
wire
wired
work