Have four of them. The green chrony one above is accurate but can't be used indoor with fluorescent lighting. I do most my testing inside so this didn't work. Little yellow one is the most inconsistant-doesn't pick up the shot most of the time. Radar x is more relieable but press and hold the button can be a pain with a pump. Clock is nice and most expensive. One thing I wish it did was record the last 15 shots not just a string of shots. You have to shoot pretty fast for the memory to kick in. It also chews through batteries quickly. I ended up putting 2 9 volts in there for longer batt life. Good luck.