"Easily one of my favorite airsoft purchases, basically the cheapest most fun airsoft gun. They use 12g CO2 cartridges so they're non-pyro. Overall the cores are well made, most part are replaceable, but if you lose the actual "striking pin" internal you now have a useless core because they don't sell that. Make sure to spray paint or duct tape you spoons with a high-vis color or you will lose them. You will need multiples, as sometimes they're duds, and sometimes people you 'nade steal them. Finding pouches which fit shells is most difficult; (F1) Pineapple grenade bodies I cannot find modern pouches for, whereas you can find many Stun/Flashbang pouches. Lastly, the body style does matter for detonation times, where the bigger the grenade body, the more CO2 to fill the body before detonating.
"Nice and cheap grenade, and takes $2 to $3 to reuse depending on where you are. Don't overhand throw them, they will break, they work best rolled and thrown short distances. I got about 10 uses before my first one broke due to the hammer starting to slip past the spoon and after it went off in my pouch I retired it. My second one is still going strong with more the double the uses with no problems yet. I like the Distraction and Sound Flash shells the best and the Flash Bang shells can be finicky if not set up perfectly. Just be careful if they don't go off.