Features Replacement Part Number: The replacement part number is 123‑181‑40630 or 123‑181‑09560, perfectly compatible. Rubber Material: The primer bulb is made of high quality rubber material, which is wear resistant and durable, soft and has good performance. Perfect Replacement: Practical replacement accessories, easy to install, can replace broken or old parts, perfect replacement. Perfect Match: Suitable for Walbro 188‑12, 188‑12‑1, for Stihl 41331212700, for McCulloch 22583400, etc. Good Workmanship: Small size, light weight, the outer diameter of the cup mouth is 18.5mm, the height is 14.6mm, and the size is standard. Specification: Item Type: Primer Bulb Material: Rubber Mouth Outer Diameter: Approx.18.5mm / 0.73in Height: Approx.14.6mm / 0.57in Package List:100 x Primer Bulb Note:Match the appropriate model size before use Package List 100 x Primer Bulb