The 360 primer has been in the HB Body range for some time as their go-to primer, 2:1 mixing ratio and can be used wet on wet. If you're looking for a good primer with a thick finish, this is the one. If you're looking for something a little cheaper which you can just throw on for a quick repair, the HB Body 305 is the one we'd point you towards.
This is what HB Body has to say about it.
"High quality acrylic primer for partial and full passenger car refinishes. Suitable for plastic and unsanded cataforesis OEM panels. 2:1 mixing ratio with H 725 Hardener for Primers FAST / SLOW or H 729 Hardener for Primers NORMAL. Its versatility enables both application at normal, medium and high film thickness with intermediate sanding or “wet-on-wet" application. The good absorption of overspray and excellent levelling guarantee outstanding results."