The Siemens 3RT1015-2AR62 is a SIRIUS power contactor in the S00 frame size, rated for switching motor loads up to 3 kW under AC-2 duty at 400 V — that's the category for slip-ring motors, wound-rotor applications, or any load where the starting current is moderate and the contactor sees frequent on-off cycles. At 24 V the contactor carries 10 A, which is the coil holding current plus auxiliary load capacity.
Side-by-side mounting is permitted with 6 mm spacing to the side, so you can pack them tight in a multi-contactor group without derating the thermal capacity. Spring-loaded terminals on the main circuit accept 2x (0.25 to 2.5 mm²) solid or stranded, or 2x (24 to 14 AWG). No screw torque to check — just strip 8–10 mm, push in, and the cage holds. That saves a few minutes per termination on a panel with a dozen contactors.
If you're comparing against the 3RT1016-2AP02, the difference is in the frame size and current capacity — the 3RT1016 is an S0 frame with higher AC-3 ratings. The 3RT1015-2AR62 is the S00 sibling, smaller footprint, lower current. They share the same SIRIUS accessory ecosystem (same auxiliary contact blocks, same surge suppressors), but the 3RT1016 won't drop into a panel cutout designed for the S00 without a DIN rail reposition.