Product Details: The Arnold Primer Bulbs Variety Pack has everything you need to keep equipment running the way it should season after season. With Arnold, you can be confident of a reliable product with accurate fit, design, material, and construction. In addition to reliable parts and accessories, Arnold's easy-to-follow instructions and extra tips will ease your equipment maintenance and assure that you get the job done right. Get your pack of primer bulbs today. These primer bulbs are for use with 2-cycle and 4-cycle handheld equipment For Troy-Bilt, Craftsman, Homelite, John Deere, Ryobi, Bolens, Yard-Man, Ryan, Yard Machines, Husqvarna and Stihl models Primer bulbs fit many Zama, Walbro, Shindaiwa, Stihl and Homelite carburetors Fits all 2-cycle and 4-cycle Zama carburetors (#0057004) Fits Walbro models WA, WT, WY, WYJ, WYK, WYL, WYP WZ carburetors that require a .755 in. OD x .560 in. HT primer bulb (#188-12) Fits HDA models and WYK carburetors that require a .680 in. I.D. x .912 in. O.D. (#188-13) Replaces Walbro #188-14, Echo 12318140630, Homelite UP-04802, UP04802, 01201, McCulloch 225834-00, Shindaiwa 20036-81670 and Stihl 4133 121 2700 Replaces Green Machine 4467213, Homelite 01201, UP04802 and Red Max 1491-61510 Pack of three primer bulbs - one of each in three different sizes