A replacement bulb for the primer on a Toro CCR 2450. Printed in TPU with the top on the build surface. Prints without supports. This replacement bulb can be epoxied in place or simply placed over the primer and pressed a few times, then stored for the next use. This design works best with soft TPUs, the higher the shore hardness, the harder it is to press. I found 92a to be a good balance of usability and rigidity.