The added random screening procedure at issue in this case involving a handheld magnetometer scan of Marquez's person was no more extensive or intensive than necessary in order to detect weapons and explosives. It utilized the same technology and reported results based on the same type of information (e.g., the presence or absence of metal) as the walkthrough magnetometer. See United States v. $124,570 U.S. Currency, 873 F.2d 1240, 1245 (9th Cir.1989) (noting that, unlike this case, "the court cannot sustain a subsequent search that differs in material respects from the search initially approved"). While it arguably constituted a "slight privacy intrusion," Pulido-Baquerizo, 800 F.2d at 902, it was reasonably confined to procedures necessary to detect weapons and explosives, including those that may evade detection by the larger, less sensitive walkthrough magnetometer.