Abstract We show that in a confining hidden valley model where the lightest hidden particles are dark hadrons that have mass splittings larger than O 0. 1 $$ \mathcal{O}(0. 1) $$ GeV. if the lightest dark hadron is either stable or decays into Standard Model (SM) hadrons/charged leptons during the big-bang nucleosynthesis (BBN). https://www.izztop.com/product-category/novelty-toys/