CONTRAC All-Weather BLOX City Packs is a specially formulated anticoagulant rodenticide which helps control and eliminate rats and mice. It contains Bromadiolone as its active ingredient with a special blend of food-grade ingredients and a minimal amount of paraffin. It will effectively kill those pesky rodents, including warfarin-resistant Norway rats and meadow voles. Its highly palatable formula is time-tested and proven effective against commensal and non-commensal rodent species so it makes a great maintenance and clean-out bait. It also features a weatherable formulation so it works in dry or wet conditions. It comes with multiple edges which is appealing to rats because of their love to nibble. The center of the BLOX has a hole to allow technicians to secure baits on tamper-resistant bait stations, nails, or wires with ease. Each BLOX weighs 28 grams and will work with most bait stations, in tight places, or can be nailed to ceilings or rafters.