SOLAREZ Epoxy repair putty is a mixture of clear, high strength, fiber reinforced epoxy resin and an amazing solar activated catalyst. There is no mixing required. Just use it right from the tube. It gels in 5 seconds, curing in 3 minutes - but ONLY when exposed to sunlight. No mixing necessary. UV curing assues complete hardening. Provides complete crosslinking Remarkably tough and resilient Contains urethanes that prevent yellowing ECO-Friendly ZERO vapors, non-flammable. Comes with 60/240 grit sand pad.