The Wrangler is an unlockable secondary weapon for the Engineer. It appears to be the remains of a wooden pistol grip implemented under an early-80's single-button style team-colored joystick, with a small, rectangular radar dish protruding from the front.
This weapon provides you with control of your sentry, allowing you to aim and fire it. While wrangled, the sentry fires twice as fast, and rockets reload about 1 second faster for level 3 sentries. This is deadly to almost all classes, as it has a average damage of 128 for level one, 256 for level 2, and 256 or 375 if rockets are fired, making it extremely powerful with it's increased health and defense shield for level 3 sentries. It also gives the sentry a team-colored translucent shield that absorbs 66% of the damage your sentry recieves. This would technically allow it to survive a Backstab or a Headshot, though neither can be preformed on a sentry. When you switch to a different weapon, the sentry powers down for 3 seconds, but returns to AI control after the time passes. During the power down time, the sentry retains the damage absorbing shield and cannot attack.