AC403 Universal Trimmer Shoulder Harness: Setup & Install Video

Install video: coming soon. Until then, follow the steps below (same as the printed manual).

Package Contents

  • 1 × Universal Trimmer Shoulder Harness
  • 1 × Universal Shaft Strap (with D-ring)
  • 1 × 26 mm Shaft Clamp Ring
  • 1 × 28 mm Shaft Clamp Ring
  • 1 × User Manual

Choose the Right Attachment Point

  • Factory hanger ring already installed? Skip this section and go to Installation Instructions.
  • Round, straight shaft - 26 mm or 28 mm: Use the Shaft Clamp Ring.
  • Curved, square, or other shaft shape: Use the Universal Shaft Strap.

No Hanger Ring on Your Trimmer? Many entry-level, battery, and curved-shaft trimmers have no factory hanger ring for the hook. Add an attachment point with one of the included adapters, mounted at the shaft's balance point (usually just below the front handle).

Option A — Shaft Clamp Ring (for round, straight shafts)

  1. Pick the clamp that matches your trimmer's shaft diameter — 26 mm (≈1.0") or 28 mm (≈1.1").
  2. Open the clamp around the shaft and hand-tighten the thumb screw until it won't slip or rotate.
  3. Clip the harness hook onto the clamp's ring.

Option B — Universal Shaft Strap (for curved, square, or other shafts)

  1. Wrap the strap around the shaft at the balance point.
  2. Feed the end through the buckle and pull tight until snug.
  3. Pull the strap tight, secure the loose end, and make sure the strap cannot slide or rotate. Then attach the harness hook to the D-ring.

Installation Instructions

  1. Put on the harness and fasten the chest and waist buckles. Adjust the straps for a secure and comfortable fit. Make sure the hip pad rests against your hip.
  2. With the trimmer switched off, attach the harness hook to the factory hanger ring or the installed adapter D-ring. Make sure the hook is fully closed.
  3. Check the balance. If needed, support and unhook the trimmer, then loosen, reposition, and retighten the hanger ring or adapter. Reconnect and check again.
  4. Make sure all buckles, straps, and the hook are secure. Secure loose straps and keep them away from moving or hot parts.

Left-Handed Configuration (Optional)

Left-handed users should complete these steps before putting on the harness.

  1. Flip open both buckle covers (front and back) on the hip pad strap and loosen the strap. Remove the hip pad from your right side (as worn).
  2. Move the hip pad to your left side (as worn) and attach the strap to the harness the same way.
  3. Tighten both ends of the strap, then press both buckle covers down to lock them. Tug the hip pad to make sure it is secure.

The hip pad is now on your left side for comfortable left-handed operation. All other parts stay in place.

Before Each Use

  • Check all buckles, straps, and the hook.
  • Confirm the hanger point cannot slide or rotate.
  • Left-handed? Complete the Left-Handed Configuration first.

Safety Warning

Ensure the hook is securely attached to your trimmer. Do not use the harness if it is damaged or loose. Always wear appropriate safety gear, including gloves and eye protection. Keep loose straps away from the cutting head and all moving or hot parts.

Looking for a set that also includes a trimmer handle? See the AltitudeCraft 2-in-1 String Trimmer Handle & 5-Point Harness Kit (a separate kit that includes a trimmer handle).

Need help? Email support@altitudecraft.com. Warranty: 1 year, plus a free 3-year extension at free-extended-warranty.