KST-120X KST 120X-06 Trimmer Spool & Blades Head Compatible with Kobalt 40-Volt Max KST 2040-06 KDLA 3040-03 String Trimmers,Pre-Wound Trimmer Line 20Ft 0.065" with Replacement Part (24 Pack)

What It Is

This is a replacement trimmer spool and blade head set (24-pack) for Kobalt 40-Volt Max string trimmers, pre-wound with 20 feet of 0.065-inch trimmer line. It’s designed for light-duty trimming around edges, fences, and flower beds.

Fitment & Compatibility

Before buying, confirm your trimmer model. This fits Kobalt KST 2040-06 and KDLA 3040-03 only. Check the deck size isn’t relevant here (it’s a string trimmer, not a mower). Verify your trimmer uses a 0.065-inch line diameter and a bump-feed head. This is an aftermarket part, not OEM Kobalt, so double-check the spool’s center hole diameter (typically 1 inch) and that the head locks onto your trimmer’s shaft. If your model uses a different line size or a fixed-line head, this won’t work.

Key Things to Know

• Quality concerns: With a 3.0/5 rating from 91 reviews, expect inconsistent line durability—some users report the line snaps easily on thick weeds or against hard surfaces.
• Installation: Simple snap-in replacement; no tools needed. Ensure the spool clicks fully into the head and the line feeds freely through the eyelets.
• Line length: 20 feet per spool is short—you’ll reload often if trimming large areas. The 24-pack helps offset this, but you’ll go through spools quickly.
• Compatibility gotcha: Some buyers report the head doesn’t fit securely on KST 2040-06 models made after 2021. Check your trimmer’s serial number and compare the head’s locking tabs to your original.

Should You Buy It

Buy this only if you own a listed Kobalt model, need a bulk pack for frequent line changes, and are okay with average durability. For heavy-duty trimming or thicker weeds, look for a 0.080-inch or 0.095-inch line instead.