At GT our windscreen repair kits come with a vacuum and pressure system as standard. For around the same budget you will be able to find 1990's technology plastic injectors sold as standard. If you want a metal injector you will have to upgrade your new kit straight away to get presumed better. 

In addition plastic injectors use 0.3ml of resin (12 drops) where as GT stainless steel kits only use 0.1ml of resin (4 drops) making them less wasteful and 66% more resin usage efficient.

With plastic injector kits you will also find you get the minimal amount of resin 5ml (20 repairs) to get you started so that you come back sooner to buy more. 

At GT we supply you 30ml of resin (150+ repairs) because we just want you to love our windscreen repair kits and enjoy using it without having to reorder resins as soon as you have started.