A level is a tool used by carpenters and architects for determining the true horizontal and vertical. The level found in period armory was blazoned a “water-level” in the arms of the Worshipful Company of Plumbers, 1588 [Bromley & Child 204]: a roughly triangular piece of wood, encompassing a plumb-line; the flat side is to chief by default.
Society armory also has the “A-frame plumb-line”, simpler but less accurate than the standard level. It dates from ancient Egypt, and was probably in use through the Dark Ages [Singer 672], but we’ve no examples of its use in period armory.
Bróccín Stratton bears: Per bend sinister sable and azure, on a bend sinister bretessed between a water-level and a fish haurient Or, three roundels azure.
Jonathan Ryder bears: Tierced per pall inverted sable, Or, and gules mullety Or, in chief two A-frame plumb lines in fess counterchanged.
Renfield Trelain bears: Vert, an A-frame plumb line argent.