Haven't found any decent models here, so I made one. As durable as it gets for that size.

Designed to be printed with a 0.8mm nozzle. Should work fine with any smaller ones. Just make the layer height ⅓ of the nozzle diameter or lower.

Also scalable to 75% for a 0.6mm nozzle and to 50% for a 0.4mm nozzle. Would not recommend scaling down more than that due to engineering reasons.

To print a cap, turn it upside down.

Feel free to remix it if you can make it better or whatnot.