The Plungers for bait syringes are for use with Roach and Ant Bait Gel Tubes and would not be used for injecting liquid insecticides/termiticides into concrete, wall voids or other areas.  If needing to inject a termiticide mixed solution in holes that have been drilled across concrete (driveways, patios, sidewalks) for the continous termite barrier  treatment, use a 1 gallon hand pump sprayer with the nozzle set to spray a pin stream spray and slowly spray ½ gallon of mixed solution into each hole across the concrete. Another option is to use a funnel and place the tip of the funnel into the hole and slowly pour the mixed solution into the funnel to work it’s way down into the hole.  Please view our Subterranean Termite Guide for more information on this process for treating across concrete.