What it is and where it fits
The Siemens 3RT2026-1BB44-3MA0 is an SIRIUS-size S0 power contactor — the kind you'd hang on a 35 mm DIN rail in a motor control panel or a conveyor line. It's current production (no end-of-life worry), with a 24 V DC coil and screw terminals for main and auxiliary wiring. No add-on auxiliary switch block, so what you see is what you get: three main poles and one normally-open auxiliary contact built in. Dimensions are a straight S0 frame: 45 mm wide, 85 mm tall, 151 mm deep. That's a compact footprint for a contactor rated to switch motor loads in the 7.5 kW range (depends on the duty). If you're cramming a panel, the 45 mm width leaves room for a soft starter or a breaker alongside.
What the ratings mean for your line
Will it survive the route? Operating temperature range is -25 to +60 °C, so it'll sit fine in a non-climate-controlled panel near a hot motor. Storage range goes down to -55 °C, but that's handling, not running. Mount it any way you like: the contactor can be rotated a full 180° on a vertical surface and tilted up to 22.5° forward or backward. That's handy when you're fitting it into a mixed row of gear.