The Siemens SIRIUS 3RT1026-1CC24 is a size S0 power contactor with a 24 VAC coil rated for both 50 Hz and 60 Hz supply. The coil tolerance spans 0.8 to 1.1 times rated voltage at 50 Hz and 0.85 to 1.1 at 60 Hz, so it holds in through brownout conditions that would drop out a tighter-coil contactor. The 45 mm width (three module spaces) and 88 mm height fit the S0 footprint common across the SIRIUS contactor family, so panel layout and busbar planning are straightforward if you're replacing or expanding an existing SIRIUS installation.
For resistive loads (AC-1), the maximum operating current is 10 A. The auxiliary contact block is a 2-pole instantaneous contact (NO/NC configurable by wiring). The integrated varistor surge suppressor on the coil means you don't need an external RC snubber for standard 24 VAC control circuits — it handles the inductive kick internally, saving a component and a wiring step. Termination is screw-type for the main circuit, accepting 2x (1 to 2.5 mm²) or 2x (2.5 to 6 mm²) solid/stranded, with a maximum of 2x 10 mm². The control circuit terminals accept 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²), up to 4 mm² max. That covers standard panel wire sizes without adapters. IP20 on the front, IP00 at the terminals: the body is touch-safe, but the wiring terminations need enclosure protection.