Compression spring replacement

It's a compression spring. It is the one used in all Savur Floats.  Unless you want spare springs to have on hand, or if you lost one, there really is no reason to buy these.   We send a new spring with all Savur Reload Kits and Floats.  This is a standard spring also sold at McMaster Carr part number: 9657K362

Compression Spring, 1.5" Long, 0.97" OD, 0.81" ID