Spray and applicator style leak detectors allow to quickly and easily detect leaks on PEX, sweat, threaded, compression, flare and other types of connections when pressure-testing the system with compressed air. Highly viscous, the formula produces large, long-lasting bubbles - even on vertical connections. MegBubble formula is non-toxic, non-corrosive and will not freeze. Compatible with plastic and metals pipes and fittings, including PEX, copper, PVC/CPVC/ABS, black/brass/stainless and many others.