That’s *LOCTITE 243 Threadlocker* - Medium Strength, 50ml bottle.
*What it is:*
1. *Product*: Liquid threadlocker adhesive by Henkel/LOCTITE.
2. *Strength*: Medium strength - blue grade. Secures bolts but can still be removed with hand tools.
3. *Features*: Works on metal fasteners. Seals threads, prevents vibration loosening, and resists oil, fuel, and coolant.
4. *Size*: 50ml bottle with precision nozzle.
*What it’s used for:*
Securing nuts, bolts, and studs on machinery, engines, pumps, and equipment. Standard in oilfield, automotive, and fabrication work to stop bolts from vibrating loose.