Horbach. https://www.amazon.com/gp/product/B08776M6GT/

The Muscle Empire brand https://www.amazon.com/gp/product/B087HLZL6S/ actually had better handling qualities, but the Horbach is even significantly more economical than that brand that it was not worth (to me).

As far as the quality of the actual product, all Agmatine *should* be the same.

Agmatine is a crystalline white powder with fairly good sticking and packing. It's easy enough to make your own capsules, even without a machine. (Using a tweezer, I just tamp the open capsule into the powder and it packs itself in, pretty much.) One 000 capsule (handpacked in this way) holds *about* 600mg of Agmatine. (Slightly more, if you're consistently good at it.)