Need sprocket adapter(washer?), unsure what I need though

[bmxmike215]

So, getting back into bmx, broke cranks, replaced Fly cranks with Profile GDH cranks so they're 19mm and I think the Fly's were 22.

I have a RNC 25 tooth sprocket, not realizing I needed a different sprocket washer/adapter I put it out and it was wobbly.  What do I need to buy to fix this, a 19mm sprocket adapter?  Should I just bring the sprocket to a local bike shop and ask?

[Sasha]

It's called a top hat washer. If you had an adapter in with your 22mm cranks then you will need a 15/16th" to 19mm washer, if not then you'll need a 22mm to 19mm one.

http://www.ebay.co.uk/itm/like/281785682570?adgroupid=13585920426&hlpht=true&hlpv=2&rlsatarget=kwd-75951449586&adtype=pla&ff3=1&lpid=122&poi=&ul_noapp=true&limghlpsr=true&ff19=0&device=c&chn=ps&campaignid=207297426&crdt=0&ff12=67&ff11=ICEP3.0.0-L&ff14=122&viphx=1&ops=true&ff13=80

Edit 23.8mm is 15/16th