fire fighting sprinkler 1.all types of fire sprinklers 2.thread size:1/2"(15mm) 3.5mm glass bulb 4.zinc,chrome plated top quality glass bulb fire fighting sprinkler fire sprinkler structure:1.frame:zinc,chrome plated2.deflector:zinc,chrome plated3.screw:zinc,chrome plated4.bulb seat:soft sealing5.spring:nickel alloy6.seal:teflon7.bulb:glass with glycerin solution,5mm sizefire sprinkler types: ...