Since Profoto no longer offers replacement batteries for their older OCF flash units (i.e. B1 and B2's), recent years have necessitated me needing to go for cheaper third-party options to continue using them. Having had success with third-party batteries for my B1 and B2 units in the past (which are still going strong after nearly 2 years of hard use) — I thought I'd give these batteries a try for my A2's.Build quality feels solid with proper fit in my A2. The battery seats correctly with no play. Sometimes the battery will get snagged or the clip will not engage, requiring re-seating – a minor inconvenience, and doesn't happen every time, so no big deal. The finish on the plastic housing has more texture on it versus the smooth plastic on OEM batteries. The sides of the battery have grooves to assist in removal instead of the indent on the original battery.COMPATIBILITY — 100%; the battery charges fine on the original charger included with the A1 and A2 series flashes, and will stop when full, even though they have a higher capacity than the OEM batteries. The battery indicator on the screen of the A2 unit itself also indicates the correct charge level of the battery, and updates as the battery depletes.SPECS — these batteries claim 3000mAh/21.6Wh, which is significantly (50%) more than the OEM A1/A1X/A10 batteries, rated at 2000mAh/14.4Wh. For context, I own a few A2 units which use the same battery form factor as the A1 series speedlights that I am using these in. The A2's included batteries have a slightly higher capacity than the A1 OEM batteries, and are rated 2450mAh/17.64Wh. I do not have the equipment to test this, but if the ratings are accurate, then these actually offer a slightly higher capacity than even the larger A2 batteries.PERFORMANCE — I've ran about 5 cycles through the battery as of this review and have gotten good flash count and recycle times that — at the very least — are comparable to the OEM batteries.I should note that during testing, I noticed that recycle times got longer as the battery drains, or heats up with repeated back-to-back high-powered pops of the flash, or when the unit is used in conjunction with the modeling light. HOWEVER, this is also an issue I've experienced to a lesser extent on the OEM batteries, suggesting that it is more than likely a function of the unit itself heating up, rather than the batteries' fault. If the unit cools down enough, shorter recycle times return. I confirmed this by swapping when the unit had heated up, and the recycle times remained higher than normal (even with a fresh, cool, OEM battery).This battery also works wonderfully with the built in LED modeling light on the A2. The battery holds charge well when not in use; some batteries are known to drain significantly even when sitting, but I have not experienced that with these, nor any of my other third party profoto-compatible batteries.The one concern may be longevity/lifespan, which remains to be seen. However, as noted above, I have used third-party batteries in all of my other Profoto strobes for the last few years with no issues, and I expect (hope?) the trend to continue. Even if the cells are of lesser quality than the OEM units, they should at least offer equal performance/capacity/longevity due to being "over-rated".5-stars — Overall, these are a solid third-party option. At $80 versus $129 for OEM for the A1/A2 series lights, the savings can be substantial if you want/need to have multiple spare batteries on hand when working on location or at an event. If you're not comfortable with third-party batteries in your expensive flash units (because, let's face it — if you're shooting with premium equipment, you _should_ be using OEM as much as possible), at the very least these can be backups-to-the-backups — "One is none, and two is one", after all.