The 24" electronic level I have was the original, the module was built into the level, not transferable. I've since bought the 72, 48, and 24" Stabila electronic levels. These are great, they have various modes, including one that tells you how far out is the surface. They also have different tones so you can tell without looking which way the level needs to move to find level or plumb. Managed to buy them at 25% off through Zoro.