I like and have used Butler Creek Lightning loaders for many years. They have a straight through design and are capped at each end. each end cap has a holder/dispenser that holds a single percussion cap. To use it, I clip it to the bill of my cap(on the opposite side of my shooting shoulder) When I shoot a deer I remove the speed loader from my cap, pop open the powder end and dump it down the barrel, turn it over pop the other cap place the powder end over the muzzle and push the patched ball all the way through the speed loader and into the barrel and with the ramrod seat the ball on the powder. Then I prime the pan and I'm ready to go. For people that use percussion rifles your percussion cap is right there on the speed loader. This only takes a few seconds. I always take a few when I go to the woods and they have came in handy many times.