Chapin 20 Gallon Hose End Lawn Sprayer (G390) can be used with Fertilizers, Weed & Feed, Fungicides, and Herbicides. We would not advise on using it to apply Talstar or any other products not labeled to be used in a hose end sprayer. Talstar P and many similar professional grade products are very thick concentrates and do not necessarily work well in a hose-end sprayer.
Per the manufacturer, the hole on top of the Chapin 20 Gallon Hose End Lawn Sprayer (G390) allows air to go in so that it will syphon properly.