These hammer weights are used and contain some small stress fractures in the plastic from regular use but we reinforced the weak spots with a good glue so they should be good for quite a bit more use and at this price you should probably buy a few extras because they have gotten so hard to find. I applied reasonable finger pressure trying to break them and discarded any that broke. These hammers will also fit the models shown below.

Roland A-90
Roland A-90 EX
Roland FP-1
Roland FP-9
Roland HP-145
Roland HP-147
Roland HP-236 
Roland HP-237
Roland HP-237E
Roland HP-245B
Roland HP-330
Roland HP-535 
Roland KR-370
Roland KR-375
Roland KR-570  
Roland KR-575  
Roland KR-575P
Roland KR-770
Roland MP-300
Roland XV-88
Roland RD-500 (type 2)
Roland RD-600