Go-Cal Replacent Battery Pack Back Catalog number: 811-9917-03 Manufacturer: SENSIDYNE Availability: In the manufacturer's stock Price on request - + Recommended 811-0920-01 Replacement Valve Caps (Pack of 2) Price on request GCU3745EF Cassette, 37mm .45µm PVC Endotoxin Free, 10/Box Price on request GCU37AE Cassette, 37mm 3pc w/ Type A/E Glass Fiber, 50/Box Price on request