3T Invest is a venture capital fund that supports early-stage companies with a positive social impact in manufacturing, energy, nuclear, and green tech sectors. They provide coaching and capital, with investments ranging from $500K to $10M, focusing on pre-seed stage startups. Notable portfolio companies include Exeger, SigridTherapeutics, Nanologica, and Mindler. 3T Invest aims to foster businesses that contribute positively to society and the environment through strategic investments and guidance.