This cap fits over the top of a backpacking trowel to protect your palm from sharp edges. 

Credit for the idea goes to https://www.printables.com/model/510991-lixada-camping-shovel-hand-protector

This model is original, designed to fit the differently-shaped trowel I purchased.

The trowel I have is from AliExpress and similar trowels seem to be available on Amazon and probably elsewhere. The model has an interior triangle that mates with the first diamond cutout on the handle to hold it in place.

No supports needed. Print it on-end as shown in the screenshot.

You can print in PLA (example print in photos is PLA) but a more weather-resistant filament like ABS or PETG may be preferable for durability.

OnShape document: https://cad.onshape.com/documents/db1eea8bcee4ecb0ed364cab/