Dsnaduo Neoprene Rubber Expansion Plugs 14pc Kit — 6 Sizes 3/4"–1-1/2" Tapered Sealing Plugs, Oil-Resistant Reusable

These are Dsnaduo neoprene rubber expansion (freeze/frost) plugs — a 14-piece set in six sizes designed to seal engine and automotive service holes from 19mm to 38mm (3/4"–1-1/2").

If you need a reliable, reusable rubber stop for coolant passages, exhaust test ports, or general service holes, this Dsnaduo kit gives a range of tapered plugs so you can match hole diameters without cutting or welding. The neoprene compound compresses to form a snug seal and resists oils and moderate heat, making the set practical for garages, home mechanics, fleet maintenance, and emergency roadside repairs.

Which hole sizes are included and how many of each will I get?

The kit supplies six different tapered size ranges to cover holes from about 19mm to 38mm (3/4"–1-1/2"). Quantities vary by range so you have the common sizes ready.

• 3 pieces for 19–22mm (3/4"–7/8") holes
• 3 pieces for 22–25mm (7/8"–1") holes
• 2 pieces for 25–28mm (1"–1-1/8") holes
• 2 pieces for 28–31mm (1-1/8"–1-1/4") holes
• 2 pieces for 31–34mm (1-1/4"–1-3/8") holes
• 2 pieces for 34–38mm (1-3/8"–1-1/2") holes

How do these rubber expansion plugs work and when should I use them?

Each plug is tapered so pressing it into a slightly undersized opening compresses the neoprene and creates a pressure-tight seal. They’re intended for temporary or maintenance use: closing coolant passages, blocking exhaust or pressure-test ports, or sealing access holes during repairs.

• Tapered profile expands to fit a range of diameters
• Neoprene material resists oil, grease, and moderate engine heat
• Reusable — remove and reinstall for multiple service cycles
• Useful for pressure testing or preventing fluid loss during work

Are these safe for engine bays and what are the material limits?

These plugs are made from neoprene rubber, which offers good resistance to oils and moderate temperatures commonly found in engine compartments. They are not a permanent replacement for metal freeze plugs or high-temperature seals, so avoid prolonged exposure to extreme heat or corrosive chemicals.

• Suitable for intermittent engine-bay use and general maintenance
• Not meant as a permanent high-temperature exhaust seal
• Inspect plugs regularly for hardening or cracking before reuse
• Replace if damaged or deformed to maintain a tight seal

How do I choose the right size and install a plug correctly?

Select a plug whose minimum tapered diameter is slightly smaller than the hole and whose expanded range covers the opening. Press the plug straight into the hole and seat it until the flange or widest section contacts the surface to ensure even compression and a tight fit.

• Measure hole diameter with calipers or a ruler first
• Start with the smaller plug in the range and push it firmly in place
• Use a blunt driver or wooden dowel to avoid cutting the rubber
• Test for leaks or pressure loss after installation

Who this is for: This 14-piece Dsnaduo neoprene plug set is aimed at DIY mechanics, professional technicians, fleet maintenance crews, and hobbyists who need a flexible, reusable way to cap service holes, perform pressure tests, or prevent fluid loss during repairs. It’s ideal when a quick, non-permanent seal is required across a range of common hole sizes from 19mm to 38mm.