The Siemens 5SL6408-8CC is a 4-pole miniature circuit breaker from the Basic Devices family, rated at 8 A with a D tripping characteristic, 400 V AC, and a 6 kA breaking capacity.
That means factory support, replacement availability, and no looming last-time-buy deadline. RoHS compliance dates from June 2013.
Mounts on standard DIN rail in a panel enclosure. Four-pole format takes 4 module-widths of rail space — factor that into your gland-plate and fill-factor planning if you're retrofitting into a crowded cabinet. The D-curve trip thresholds (10–20× In magnetic release) mean it pairs with downstream loads that draw a hard start; verify your load's inrush profile against that band before committing the BOM line.