Is this useable?

[redgum]

I picked through a new bucket of wheel weights today and found quite a mixed bag.
There a re the obvious steel ones, some clearly marked (some not so clearly) zinc ones, with Zk stamped on them ( although I thought they should say Zn )
Then there are these ones that appear to be lead but have Gr & Pb on them. Any hints on wether they're useable or not?
http://i141.photobucket.com/albums/r49/redgum94/WW_1.jpg

[Bob Jones]

It's hard to tell the size but maybe the marking means "50 grams Lead"? If they're a little under 2 ounces that's what it would be.

[redgum]

Sorry, They're about an inch by an inch and they're the 'stick-on type weights (which used to be soft lead, but these days i'm trying to exercise caution)
:)

[Pepe Ray]

Pb stands for Plumbum, the chemistry name for lead.