The B&M NAG-1 Locking Transmission Dipstick was designed to allow for a quick and easy check of the automatic transmission fluid level and quality by the vehicle owner/operator without having to go to the dealership. Constructed of billet steel and black mil-spec anodized aluminum 6061-T6, this rugged unit allows for both cold and warm fluid level checks and is meant to be left in the vehicle and locked into place. Additional features include an engraved B&M logo, locking knurled handle cap and temperature range engraved indicator end. Fits the NAG-1 automatic transmission used in the 2006 to 2012 Dodge Charger, 2005 to 2008 Dodge Magnum, 2008 to 2012 Dodge Challenger and 2005 to 2012 Chrysler 300 with a 6.1L or 6.4L V8 engine.