Sturdy aluminum body. Quick Closing. Metal air distributor. Discharge valve. ¼” Standard Connection. The new 3900 Plus pneumatic sealers are a compact, efficient and light solution for everyday needs in any workshop. These pneumatic guns are very useful when it comes to structure assembling, repairs and windshield set-ups, amongst others. There are two versions: the 3900 Plus for sealants in cartridges and the 3900 Plus M for sealants in sausages. Both versions include a trigger with discharge valve, which guarantees a great precision and control. The metallic internal parts assure a long working life. Besides, those parts do not require any manipulation neither any maintenance. Its body is made of high resistance aluminum. The front part on the 3900 Plus is made of non-deformable plastic. The 3900 Plus sealers are a very strong product capable to work for long working hours.