One-part spray insulation comes in cans that dispense that material either via a straw or "gun" applicator. One-part foam is good for sealing small holes, but isn't cost-effective for large jobs. It can also need a long time to set, and it doesn't adhere well to ceilings or overhead surfaces. Two-part spray insulation comes in two-tank kits and can also be installed from truck-mounted rigs. Two-part spray foam adheres better, takes less time to set and is quick to apply. However, it can be expensive, and it requires specialized personal protective equipment (PPE) to dispense. Also, many two-part foams are best dispensed at warmer temperatures (above 75° F).