Unirac SM Micro-inverter mounting T-bolt, Integrated Bonding, 1/4" x 3/4" stainless. 20 packSolarmount pre-assembled stainless steel bolt & nut, attaches and bonds microinverter to rail. Washer at base keeps bolt upright for ease of assembly. Product dimensions: 1.4" x 3/4". Warranty: 10 years.