A:Answer Hi Melony! If it’s a replacement strap you are after, don’t worry too much about model numbers you just need to make sure the strap is listed only for the Runner or the Multi-Sport. If listed as compatible for; Runner 2, Runner 3, Spark or Spark 3 it will not be compatible with your watch. Let me know if there is anything else we can help with! Sorry about the delay in our reply. Cheers.