Homelite Compression Spring part# 06713 was used in the bump head of the following Homelite String Trimmer models; ST185, B25C, B25S, BC1600, D825CDP, D825SB, D825SD, D830CA, D830CB, D830CD, D830SB, D830SBA, D830SBA, F2020, F2040, F3040, F3050, GST, GST18, HBC18, HBC30, HBC30B, HLT15, HLT16, HLT17, and HLT18. Even if your model is listed here, all Homelite parts are UT and/or serial number specific. Please refer to a parts breakdown for your particular model and UT number to assure that this is the correct part for your machine before you order.