I have a 502 (straight) that I'd gladly let go -- but I wouldn't recommend it. Just get the 554 or a swaro STC straight away. Not worth wasting your time to mess around with the 502 to be honest. For example, I find it's barely useful at the gun range past 200 yards. For archery to 80, it works. I try to mess around with it occasionally at the truck but I never put it in my backpack because I know it won't help with finding game. It has a very narrow field of view and lacks resolution. I used an STC to find an elk at 2.5 miles, it was immediately visible when I panned past it on the mountainside, and I could see the antlers and all. I put the 502 on a tripod next to it and I could not even see that the elk had antlers at all. I compared the two scopes at each of their zoom levels. (I find 20-25x worked best -- so I'm gonna try some sig image stabilizers and maybe forget scopes altogether). Another time, I found deer at 800 yards with good 8x binos on a tripod. I tried the 502 and could not break them out in the low morning light. Once the sun rose more I tried to pick apart the cover with the 502 but could not discern stick from hide although I knew the deer were there. I have heard the 554 is comparable to the STC, but the vortex lightweight spotter also had good reviews. The 502 is good enough to mess around with, but doesn't make anything look better than good binos on a tripod in my opinion. And it's easier for me to find things using binos.