FKM Rubber Strap for Longines Hydroconquest L3 Series – 21mm Curved End

Description

Quick answer: This strap for Longines HydroConquest is an aftermarket FKM rubber strap with a 21mm curved end for the HydroConquest L3 Series (L3.742, L3.642, L3.781, L3.782). It measures 116mm + 81mm and comes with an adjustable or a standard folding buckle.

Which watches does it fit?

It fits the Longines HydroConquest L3 Series references below, all with a 21mm lug width; the curved end follows the shape of the case.

Model / reference	Size
Longines HydroConquest L3.742	21mm
Longines HydroConquest L3.642	21mm
Longines HydroConquest L3.781	21mm
Longines HydroConquest L3.782	21mm

Specifications

Feature	Detail
Material	FKM (fluoroelastomer) rubber
Lug width	21mm
End	Curved end
Length	116mm + 81mm
Buckle	Adjustable or standard (ordinary) folding buckle
Colours	Black, Blue, Green, Gray

Options

• Adjustable folding buckle: allows fine micro-adjustments for precise comfort.
• Standard folding buckle: secure, clean and easy to use.
• Colour: Black, Blue, Green or Gray.

Why choose FKM rubber

FKM is a fluoroelastomer rubber that resists heat, chemicals, UV, salt water and sweat, so it suits a dive watch like the HydroConquest. It stays soft and flexible for daily wear, and the curved end sits flush against the case. If you also own a Conquest GMT, see our FKM rubber strap for Longines Conquest GMT L3 Series.

How to fit it

1. Lay the watch face down on a soft cloth so the case and crystal are protected.
2. Use a spring bar tool to compress the spring bar at each lug and lift the old strap away.
3. Fit the spring bar into the new strap, set one tip into the lug hole, compress the other tip and let it click into place.
4. Tug gently on each side to check it is locked in. Never open the case back: the strap attaches only at the lugs.

Frequently asked questions

Which HydroConquest references does it fit?

L3.742, L3.642, L3.781 and L3.782, all with a 21mm lug width.

What is the difference between the two buckles?

The adjustable folding buckle allows micro-adjustment of the length; the standard folding buckle is a simple, fixed folding clasp.

Is it suitable for swimming and diving?

Yes. FKM rubber is waterproof and resists salt water, sweat and UV.

See all straps for Longines watches, our watch band size guide, or the bracelet for Longines HydroConquest.