FanSweeps include 3 t-lock ports built into the base plugs for reduced chance of cross ignition and multiple firing options. Can be Fired: L to R R to L Center Out Outside in Each FanSweep is wrapped in a glossy black paper which is semi-waterproof and holds up well to small amounts of light rain. Each slice comes in its own plastic bag which can be used for 100% water-proofing in extreme conditions. Just match the device and seal it up with clear plastic packing tape. Connecting fuse is covered with thick foil tape. Packing these in tightly together is no problem. This assortment consists of SE227A, SE227B and SE227C