Do you need a caulking gun with a barrel gun format? The Tajima Convoy JUST Caulking Gun is an excellent choice with a heavy duty metal frame. This gun provides a 7:1 ratio, because of a twin thrust dispensing system and auto-flow stop. As a result, you’re assured of a smooth application with low to mid viscosity adhesives! You’ll receive a 9.45″ (240mm) cartridge gun comprised of a robust, yellow metal frame. With this caulking gun you’ll experience an excellent result when sealing.