A disconnect device for use in oil well and gas well servicing operations. The device comprising a mandrel having one or more locking formations, and a hollow, female member in which the mandrel is releasably securable. The female member includes one or more lugs that are moveably retained relative to an inner surface thereof by a first retainer member engaged with at least one retainer formation formed in each lug. Each lug includes one or more locking formations. The disconnect device includes a second locking member that is moveable into and out of engagement with the retainer formation of each lug respectively to lock the lug in the first position and release it therefrom to permit its movement to the said second position.