One of the grenade on the left of the batarangs (not the fat ones, the regular angular ones) is actually of a real flashbang grenade brand, CTS,
https://www.combinedsystems.com/products/?cid=92, the grenade itself looks a lot like the 7290 flashbang model, except the label of the BvS grenade shows a blurry "model 6...something" and no flashbang mention. I can't find any grenade on their website that fits that label, so maybe they custom made the label, which won't be hard to do once we have a clear picture. Once again, an airsoft replica of the 7290 model can be found around if you want, it's also out of stock in most sites, but I found some on ebairsoft. Just look for CTS dummy flashbang. Or ebay actually.
Regarding the grenade launcher, it has two things attached to the side RIS rail, I thought it might be rail covers but it's a bit think for that, so I think it's actually the base mount of a scope of something like that, if someone recognise from what optic it could come from, let me know !
Edit : I have no idea why there is a ultron down there !