Conserving space with high-density housing, DIN-rail mounted circuit breakers are available in 3 varieties. QZ supplemental protection or UL 1077 breakers come in 1-, 2-, and 3-pole versions rated from .5–50 A, while QL branch circuit or UL 489 circuit breakers come in 1- or 2-pole variants with ratings from .5–25 A. For DC applications, QY series is rated from 1–50 A at up to 80 Vdc and carries UL489 listing.