Ul style"margin-top0px; padding-top 5px; padding-bottom 5px;" blade is constructed 1/8" thick steel spider (3-prong mount between blades and hub) designed with 3 heavy duty spring steel blades each blade securely riveted with three " round head solid steel rivets and are statically balanced guard has instant opening hinge feature for ease of maintenance and cleaning guard is constructed with 6 gauge outer and radial rib wire size and 11-1/2 gauge spiral wire size blade and guard meet all safety standards including osha ul probe clearance between the guard and blade at any point is not less than 2-1/2" (min. 1-1/2" clearance on 20" model) 8 front to rear guard positive locking fastening loops w/hinge capability (6 fastening loops on 20" guard) guards fasten securely to motor using 4 motor thru-bolts