ThinkWe is a Chinese manufacturer specialising in PV rapid‑shutdown (RSD) and DC safety devices for residential and small commercial solar systems. Their most widely used product family is the TW‑RSD firefighter safety switch series, which provides string‑level rapid shutdown using electronic isolation and MC4 plug‑and‑play connectors.

​

ThinkWe firefighter safety switches (TW‑RSD series) are compact, MC4‑based rapid‑shutdown devices designed to drop PV array voltage to <30 V during emergencies. They are popular in EU residential systems because they are cheap, easy to install, and compatible with any string inverter.