New Pack of 5 Snap in Primer Bulb Fit for Walbro 188-512-1 Wt-23a Wyj-33 Wyj-86 Ryobi 791-683974 B 683974 Replace Stens 615-764 Walbro Wt-119c (5, Round socket) Replace manufacturer part number: 188-512, 188-512-1 CRAFTSMAN RYOBI UP04033 300780004 300780001 Fits Poulan 35879158 35879558 35879898 3587952 35879556 35879516 3587958 35879518 HOMELITE HLT28 ST145 ST155 CS50 CS4018 CS5020 D4150B D450B D4550BC CS40 Please compare the sizes with your old bulb carefully, make sure it fit