This table compares the characteristics of the 944L with its predecessor, type 944U. On the exterior, the two series are mechanically identical, and they are offered in the same capacitance and voltage ranges. Internally, 944L series capacitors are constructed in a way that minimizes their equivalent series inductance (ESL) while reducing their equivalent series resistance (ESR). Due to Lenz's Law, (V = -L di/dt), high stray inductance can cause voltage to surge above the published rating of the switching device, potentially causing its failure. The 944L’s low ESL helps to minimize the voltage spike that scales with increased switching speeds. Another advantage of the 944L is that its lower ESR reduces internal heating. At high switching speeds, component heating produces system losses that contribute to shorter component lifetimes and other system inefficiencies.