The Dyna-King Cement Reservoir is designed to give you a lifetime of service while preventing unnecessary evaporation and all but eliminating nasty spills. Machined of solid aluminum with a heavy duty base for stability to help prevent spills. Air tight seal, No caps to unscrew To begin using the reservoir, rotate the bodkin applicator between your thumb & forefinger, thus breaking the seal between the o-ring & the reservoir cap. Giving the bodkin a slight twist will ease removal from the cap. Lightly press downward on the bodkin after use, to engage the reservoir seal.