A check plug that incorporates a gravity-induced attached swiveling dipstick component is provided. Such a device facilitates the measurement of fluid levels for gear system housings without the need for traditional high profile, cumbersome methods and tools. The swivel aspect coupled with a suitable connected dipstick measurement component allows the user to open the housing through a screwed-in (or other reliably connected) plug and raise the plug to a proper level to read the fluid level on the dipstick measurement component. Once such a measurement is completed, the plug can be placed back in a secure manner to the target housing and the dipstick will remain swiveled downward towards, at least (and preferably immersed to a certain degree) within the subject measured fluid. The method of performing such a measurement with the inventive check plug is also contemplated herein.