FCD SBT Battery Tool for Trijicon RMRHD & SRO FCD SBT Battery Tool for Trijicon RMRHD & SRO by Forward Controls Design Trijicon's SRO and RMR HD are among the best open emitter MRDS in the market. SRO has a battery life of about 3... MSRP: Was: Now: $20.00 Add to Cart