This document describes a modified public goods game between 4 players where at least 2 players must contribute for the public good to be available. If the public good is available, each player gets a payoff of 1 from it. Each player knows their own contribution cost ci but has incomplete information about other players' costs, which they believe are uniformly distributed between 0 and 1. The document asks to find all symmetric pure strategy perfect Bayesian equilibria of this game.