Birta dhalada aan korka lahayni waxay isticmaashaa fireemo ka dibna geli muraayadda kulul, ama ku xidh muraayadda dhalaalaysa biibiile, ama waxaad ku hagaajin kartaa muraayadda dhalaalaysa bilal.Qurxinta dusha sare ee birta leh ee qaro weyn: 10mm (3/8 ″), 12mm (1/2 ″)
Qurxinta aluminium biibiile waa 5mm (1/5 inch), 6mm (1/4 inch)Midabka: Muraayadaha cad, Muraayadaha Naxaasta ah, Muraayadaha Cawlan, Muraayadaha madaxa, Muraayadaha la qooyayHeerarka kormeerka: ANSI Z97.1,16 CFR1201,CAN CGSB 12.1-M90,CE-EN12150