Littelfuse makes electronic components that protect, control, and sense electrical power. Its core products are circuit protection components — fuses, circuit breakers, and surge suppressors — that are embedded in electronics, vehicles, and industrial equipment to prevent damage from overcurrents and electrical faults. Littelfuse also makes power semiconductors (MOSFETs, IGBTs, thyristors) used to convert and regulate electrical energy, and sensing components that monitor temperature, position, and occupancy in automotive and industrial applications. The company operates through three segments: Electronics (~56% of revenue), Transportation (~28%), and Industrial (~15%). Customers include automotive OEMs and Tier-1 suppliers, industrial equipment manufacturers, data center operators, and electrical utilities. Littelfuse sells through direct sales, distributors, and manufacturers' representatives, with Arrow Electronics accounting for roughly 9-11% of total sales and China representing ~24% of revenue. Because Littelfuse's components are required to meet safety standards, demand tends to be non-discretionary. The company's economics are driven by content per platform — as vehicles, data centers, and grid infrastructure migrate to higher voltages and power densities, protection requirements grow more complex and the dollar content of Littelfuse's products increases. Once designed into a customer's platform, Littelfuse's products are costly to replace, making revenue streams durable. M&A is a core part of the strategy; recent deals include Basler Electric, which added grid and utility protection solutions, and C&K Switches, which added electromechanical switches to the Electronics segment.