Siemens SIMATIC S7-300 Series Input Relay Module 16 Inputs, 20.4 → 28.8 V dc, 125 x 40 x 120 mm. Input Type: Digital. Length: 125mm. Width: 40mm. Depth: 120mm. Minimum Operating Temperature: -25°C. Maximum Operating Temperature: +60°C. MPN: 6ES7321-1BH02-0AA0