Prodec Heavy Duty Caulking Gun / Mastic Gun (also commonly known as a Skeleton Gun, or Silicone Gun). Dripless design which automatically disengages once you let go of the trigger, as opposed to the usual manual release (although this does mean you can't really use the hooked bar as a belt hook). Some people prefer this system. Standard type sized 11 inch frame takes all 300ml, 310ml and 400ml mastic and caulk cartridges.