Final selection of intervention items. A small flip-top water bottle (1a) permits IDUs to add approximately .05 cc water drops directly to drug powder in cookers and to clean injection syringes by backload rinsing. A preparation syringe (1b), a type of ancillary equipment not used for injecting, permits IDUs to pull up a measurable amount of water to add to drug powder, an alternative to producing water drops with the small water bottle. The Sterifilt filter (1c) attached to a preparation syringe (1d) eliminates the need for cotton or cigarette filters. Drug solution, having been filtered and drawn up into the preparation syringe, is transferred to an injection syringe (1e). The intervention kit (1f) includes a flip-top water bottle, cooker, preparation syringe (La Criolla), Sterifilt filters, and bottle of alcohol sanitizer.