Everhard MM21120 - Check-N-Fold Folding Seam Tool

Designed for fast, reliable field inspections, the Check-N-Fold gives you a pro-grade seam probe that folds safely into a compact handle for pocket or belt carry. The radiused tip and angled geometry deliver clear tactile feedback without gouging, while the secure lockup and grippy handle keep you in control around laps, corners, and penetrations on TPO, PVC, and EPDM. It’s the seam tester you’ll actually keep with you—because it’s built to disappear in your pocket when the job moves.

Key Features

• Folding, low-profile design: probe folds into the handle for safe carry and quick one-hand access
• Secure lockup: positive locking mechanism holds the probe rigid during testing
• Radiused, corrosion-resistant probe tip: concentrates feedback while helping reduce puncture risk
• Angled/offset head: better line-of-sight and leverage in tight details and terminations
• Ergonomic, textured handle: confident grip with glove-friendly contours
• Pocket/Belt ready: integrated clip and lanyard hole; easy to keep on you all day
• Field-tough build: durable hardware and finish for daily jobsite use
• Membrane-friendly: suitable for TPO, PVC, EPDM and other single-ply systems
• Made in the USA quality consistent with Everhard’s professional roofing tools

Extended length: 8″ overall when open. 

Probe/extension: Heat-treated steel extension ≈ 3-1/4″. 

Probe/Hook material: Zinc-plated, hardened steel; locks open and folds into handle. 

Locking mechanism: Liner-lock with oversized thumb opening for easy fold-away. 

Handle: Strong, textured plastic with finger grips and non-rollaway shape; belt clip for carry. 

Weight: ~0.250 lb (0.11 kg). 

Package quantity / UPC: 12 per carton; UPC 095412211205.

• Unlock the liner lock and unfold the steel hook until it locks open.
• Hold the handle firmly, positioning the hooked tip at the start of the seam.
• Slide or trace the hooked probe along the welded seam to inspect for voids or bad welds.
• Maintain consistent, gentle pressure — don’t pry or gouge the membrane.
• After inspection, fold the hook back into the handle by unlocking the liner lock.
• Ensure it fully retracts and locks closed before storing or clipping it to your belt.
• Wipe the probe clean of debris or adhesive and store the tester in a dry location.

Q: What is the MM21120 used for?
A: Fast, reliable inspection of single-ply roofing seams—finding skips/voids, checking corners and terminations, and verifying weld integrity on TPO, PVC, and EPDM.

Q: How does the folding/locking design help on the roof?
A: The seam probe folds safely into the handle for pocket/belt carry and locks solidly open (liner-lock) during use, giving you leverage and control without an exposed tip between checks.

Q: What are the key specs and materials?
A: About 8″ overall when open with a ~3.25″ heat-treated steel extension; zinc-plated, hardened steel probe; textured plastic handle with belt clip; approx. 0.25 lb total weight.

Q: Any tips for safe, accurate testing and care?
A: Use light, consistent pressure; glide along the seam (don’t pry); keep the tip smooth and clean; wipe dry after use; and fold/lock the tool closed before clipping it to your belt.