Marc Petitjean Mono Lock

Marc Petitjean Mono Lock is a knee-mounted monofilament leader-holding tool designed to keep a leader firmly anchored while fishing knots and connections are tightened.

The Mono Lock fastens around the angler’s knee with an adjustable strap, creating a secure fixed point. With the monofilament held in position, both hands remain available to form, lubricate and cinch the knot progressively.
This arrangement provides controlled knot tightening without resorting to holding heavy monofilament between the teeth or wrapping it tightly around the fingers. It is particularly useful for complex friction knots and stronger connections that become awkward when the angler has no fixed point against which to pull.
The tool supplied by troutcatchers, is straightforward enough for a beginner to operate, although it will be most valuable to intermediate and experienced salmon, predator and saltwater anglers who regularly construct heavier leaders.

Marc Petitjean Mono Lock key features and benefits

• Holds a monofilament leader securely while connections and knots are tightened.
• Leaves both hands available to form, control and cinch the knot.
• Adjustable strap fastens the tool around the knee.
• Functions as a stable third point of control when working with stronger leaders.
• Helps the angler apply smooth, progressive tension.
• Useful when constructing salmon, pike, predator and saltwater leader systems.
• Can be used at a rigging bench, on the bank or from a stable seated position in a boat.
• Reduces the temptation to grip heavy monofilament using the teeth or wind it around the fingers.
• Purpose-designed for holding monofilament rather than being an improvised knot puller.

Marc Petitjean Mono Lock top tips

• Fasten the adjustable strap firmly around your knee without making it uncomfortably tight.
• Work from a stable seated position before placing a strong connection under tension.
• Practise with spare leader material before using the tool on a finished leader.
• Check that the monofilament is held securely before beginning to tighten the knot.
• Apply tension gradually and evenly rather than using sharp pulls.
• Lubricate monofilament knots where required before drawing them tight.
• Inspect the leader at the gripping point and immediately beside the completed knot.
• Keep hooks, swivels and other components directed away from your body.
• Do not use the tool as a breaking-strain tester.
• Rinse and dry it after saltwater exposure.

Marc Petitjean Mono Lock FAQ

What is the Marc Petitjean Mono Lock used for?
It holds a monofilament leader while the angler tightens knots and connections. The knee strap provides a fixed point, leaving both hands available to control the knot.

Does the Marc Petitjean Mono Lock tie knots?
No. It does not form or tighten knots automatically. It holds the leader securely while the angler forms and cinches the chosen knot.

Is the Mono Lock suitable for ordinary trout fishing?
It can hold monofilament, but it is generally unnecessary for routine fine trout tippet. Its main advantage is seen when working with heavier leaders or demanding connections.

Can the Mono Lock be used for saltwater leaders?
It can assist with monofilament leaders used in saltwater fly fishing. The tool should be rinsed and dried after exposure because a corrosion-resistance rating has not been published.

How does the Mono Lock differ from the Hand Saver?