The document discusses using Higgs boson pair production in vector-boson fusion (VBF) to probe the hhVV coupling. VBF Higgs pair production provides unique sensitivity to this coupling. While the standard model rate for VBF Higgs pair production is small, it can be substantially enhanced in composite Higgs models with new strong dynamics. Preliminary results indicate the hhVV coupling can be measured with 25-30% precision at the LHC with 300 fb-1, improving to 10-15% precision with 3000 fb-1. The FCC could determine the coupling with few-percent accuracy. Analyzing the boosted 4b and 2b2l final states allows probing deviations in the hhVV coupling growing with di-Higgs mass.