I'm looking for a spare box. Chrome boxes are 'no longer available' (the 'not for a lot of under 3000rpm' app note on that box makes it not a good fit anyway), orange boxes seem to be made by all sorts of unknowns and are therefore an 'unknown' I'm not interested in. I see a unit made by 'HyRev' that is available for a reasonable price. It's listed as being good to 7500rpm. This box is for my 40+ year old pet Duster. I don't race it anymore, but it does see 7000rpm once in awhile just for fun. Is anyone here familiar with the brand that might say it's a worthwhile box? Or not? Thanks.