Genuine Casio replacement rubber packing/o-ring in black. 
 
Made for the following model(s):
GA-1100RG-1A, GA-1100GB-1A, GA-1100KH-3A, GA-1000-9B, GA-1000-8A, GA-1000-1B, GA-1000-1A, GA-1000-4B, GA-1000-2A, GA-1000-2B, GA-1000-4A, GA-1000FC-1A, GA-1000-9G, GA-1100-2A, GA-1100-1A, GA-1100-1A3, GA-1100-2B, GA-1100-9G, GA-1100SC-3A, GA-1100-1A1
 
DW-6700-1V, 
 
EFE-300SB-2AV, PRG-280-2, EFE-300SBSP-1AV, EFE-300SB-7AV,
 
PRG-280D-7, PRG-280-1,