ka crank pulley question

[f2x phantom]

Ok, so i bought a UR crank pulley off a friend for $50. I haven't installed it yet or anything, but i was wondering how much the stock crank pulley weighs. The UR pulley i got just doesnt seem that light to me. Does UR even make any "heavy/stock weight" crank pulleys?

I just wana make sure the UR pulley i have is indeed significantly lighter than my stock one before i get diggin into my pulleys.

I heard OBX is crap for crank pulleys, but i did get their accessory pulley set. anyone installed these yet? good? bad?

thanks