The photos are an example of a custom design - the top of this bar plug is blank, and either available as is, with text, or with an image.
This is a bicycle handlebar end plug made for handlebars with an internal diameter of 20.5mm and outer diameter of 24.5mm. Originally these were made for Takhion handlebars, and since they were successful I wanted to offer up a blank version in case you want to customize your bars a bit.
I'm opening up the ability to customize using Shapeways tools, or you can have me make something more to your liking.
Looking for a specific size or something custom? Please ask!