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 owneroperator 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.