[8x AA] I needed to make sure that my EX 600EX-RT Speedlite remained ready to fire while on the other side of the room when radio synced with the camera on the strobe and it works everytime with battery life to spare at the end of a long assignment. Very light weight since it really just holds 8 AA batteries to boost the ones in the strobe itself, but it does the job

[0.85 lb] I was concerned about the problem with the pins on the cheaper model. No problems here.

[Belt Loop] previously I had an off-brand external unit that was unreliable. This Canon unit is a powerhouse that supplies reliable non-stop flash power when needed.

[0.85 lb] I use these primarily for weddings, engagement sessions, events, and just about any other time I'm pushing my Canon 600 series speedlites hard. Operation is extremely simple, you put batteries in, plug it in, and the unit automatically turns on and off with your flash. I really feel the price is outrageous for a simple AA battery pack with some temperature sensing features. That said, I'm sticking Canon OEM for this type of purchase because I'm not going to risk burning up a $570 600EXII-RT speedlite with a third party unit. The included case is of limited utility, it works fine if you're mounting on a belt loop, but really won't help with mounting any other way. Fortunately, they include a nice 1/4-20 screw through the middle of the unit. I use this to mount to a Matthews Super Mafer Clamp to affix the battery pack to light stands, tripod legs, etc. I find this configuration to be ideal and highly recommend it if you are using this for off-camera speedlite work.

[Belt Loop] I used this at a dog show this weekend shooting win photos. It works great!

[8x AA] Great when shooting on camera flash

[Belt Loop] Good packaging. Delivered in good condition. Tested and worked perfectly with my ex600rt.

[Belt Loop] So happy with this purchase. Really helps with recycle time on my Speedlite for event shooting. Worth every penny!

[Belt Loop] The Bolt P12 for my Canon SB-5000 is a must have. As a fashion photographer, I have not had to change the batteries on my SB-5000 since I got this. Wish I had it years ago. For BTS, Red Carpet, Step and Repeat and Portraits this is an amazing tool. Consistent fast refresh power when others are changing batteries. Worried? Don't. The side LED's indicate your power at all times. GREAT PRODUCT. Don't think about... JUST GET IT

[8x AA] I am using this with the Canon 600 ex-RTII II flash. According to the manual the flash recharging time increases three fold with the battery pack, but to me it seems like it is even more powerful than that. It sits in a case that can be easily placed in your pocket, attached to your belt via the loop on it or attached to your flash bracket or tripod with the Velcro strap that comes in the case. I am thrilled with the purchase and only regret is that I did not get this sooner.