KST-120X Weed Eater String Spool Replacement, 0.065" 20FT Trimmer Line Spool Compatible with Kobalt 40V KST 120X-06 & KST 2040-06 String Trimmer Head, Dual-Line Weed Wacker Spool, 6-Pack

What It Is

This is a 6-pack of pre-wound dual-line trimmer spools, each loaded with 20 feet of 0.065-inch diameter trimmer line. Designed specifically for battery-powered string trimmers, it’s a direct replacement for the KST-120X head used on certain Kobalt 40V models.

Fitment & Compatibility

Before buying, confirm your trimmer model is one of these: Kobalt KST 120X-06 or KST 2040-06. These are the only models explicitly listed as compatible. The spool uses a 0.065-inch line – thinner than standard 0.080 or 0.095 lines – so it won’t fit heads designed for heavier line diameters. It’s an aftermarket part, not OEM Kobalt, but the spool dimensions (inner hub, outer diameter, and line exit slots) match the KST-120X head. Measure your current spool’s diameter and hub hole to double-check if your model isn’t listed.

Key Things to Know

• Quality vs. OEM: At 4.0 stars from 75 reviews, it’s decent for the price, but some users report the line is slightly more brittle than Kobalt’s OEM spools, potentially breaking more often on thick weeds.
• Installation: Pre-wound means no winding required – just pop out the old spool, drop in the new one, and thread the lines through the head’s exit holes. Takes under 2 minutes.
• Line Gauge Trade-off: 0.065-inch is light-duty. Great for grass and light weeds, but it’ll struggle with brush or thick overgrowth. If you hit heavy stuff, expect frequent line advancement or breakage.
• 6-Pack Value: $13.29 for six spools is roughly $2.20 each – cheaper than buying individual OEM spools. But if your trimmer uses line faster (e.g., frequent bump-feed), you might need more spools than expected.

Should You Buy It

Buy this if you own a Kobalt KST 120X-06 or KST 2040-06 trimmer and primarily cut grass or light weeds on a small to medium lawn. It’s a cost-effective, no-fuss replacement that saves winding time. Skip it if you need heavy-duty line for thick brush or if you prefer the longer life of OEM Kobalt spools – in that case, pay more for the genuine part.