Buffer weight spacers

[bobcatdriver]

Sorry in advance for the mundane question, but does anyone know what the buffer weight rubber spacers/pads are made of? They seem just like neoprene. I took apart a carbine buffer about 6 months ago, and finally got around to ordering some tungsten weights. I had put the spacers in a small zip bag, and now the bag is nowhere to be found. I know KAK sells them, but $10.00 shipping for an item that could be sent in an envelope blows. If they are neoprene, I can go uptown and buy a sheet of it for less than that.

[lysander]

Buna-N (aka, nitrile or NBR), 70 Shore A hardness, 0.071" thick.

EDIT: While your uptown buy a 17/32 punch.

[bobcatdriver]

Buna-N (aka, nitrile or NBR), 70 Shore A hardness, 0.071" thick.

EDIT: While your uptown buy a 17/32 punch.

Nitrile, yes, thank you. Don't know why I was thinking about neoprene as it's pretty spongey. Mechanic I know has a punch set that I can use. Thanks again.