The XSM-20 is a 20 pack of magnetic prewire device used to securely bury wire behind a wall or ceiling surface. Accurate to 1/4" through 1" of wood and is re-usable. Xspot mini is designed to work with small gauge wire and/or multiple conductors for anything from speakers, temperature sensors to thermostats. Designed with security applications in mind. Xspot-minis work very well with security motion, glass break, fire, carbon monoxide or just about any kind of wired sensors. Wires are located with Xspot-minis and can be pulled out through a 1" opening, setting a new standard in residential and commercial wiring. The only limit is someone's imagination. Xspot is reusable and made from 65% recycled products, while all Xspot products are "Xspot red" for easy recognition they are also GREEN. Ships FREE USPS Priority mail within the US in 1-5 days. International orders are given a shipping credit towards freight and taxes.