Fuse Block, Fits Fuse Type Industrial, Fuse UL Class H, K5, 0 to 30 A, Number of Poles 1, 250V AC/125V DC, For Fuse Size 2 in L x 9/16 in dia, Compatible Fuse Series NLN, NON, OT, REN, RF, RLN, Series HM, Nonindicating, Nonrejection, Fuse Block Design Open, Wire Range 18 to 10 AWG, Mounting Style Bolt-Down; DIN Rail, Body Material Thermoplastic, Connector Type Screw with Quick Connect, Height 2 in, Width 1 in, Length 3.2 in, Spring Reinforced Clip Yes These fuse blocks are compatible with UL Class H and K fuses that commonly provide overcurrent protection in older HVAC installations. They're used with Class H fuses for a noncurrent-limiting system with small interrupting ratings or Class K fuses for a current-limiting system with high interrupting ratings. Fuse blocks with spring-reinforce.