Surface Resistivity

A real ESD mat is static dissipative, roughly 10^6 to 10^9 ohms, so charge drains slowly. “Anti-static” with no figure is a warning sign.

Heat Resistance

If an iron or hot air lives on the bench, choose two-layer rubber or silicone. Vinyl and polyester scar and melt.

1 MΩ Resistor

Every proper wrist strap cord has a 1 megohm resistor. It drains charge gently and limits current if you touch something live.

Snap and Ground

Bands use 4 mm or 10 mm snaps that don’t interchange. Check how the kit reaches earth: ring lug, ground plug or clip.

Size

A mat only protects what sits on it. A 2 x 3 ft mat fits a station, a board and your parts; a small pad suits one module at a time.

The cheapest way to take a hobby bench from bare desk to grounded. Kaisi’s kit is a silicone mat rated to 932°F, so irons, hot tweezers and solder blobs do no harm, moulded with screw wells, a ruler and small parts areas that are handy when you open a smart plug or a commercial ESP32 device. The box adds a wrist strap, grounding wire and grounding plug, giving you a complete path to earth. The working area is modest, and there’s no published compliance data, so think of it as a big step up for a hobby bench rather than a lab-grade worksurface.

For makers who work on the kitchen table, at a makerspace or on site installing ESP32 sensors, iFixit’s mat rolls up into a bag and unrolls into a 24 x 24 in dissipative worksurface. It comes with a grounding snap and wire with a clip plus a 1 MΩ wrist strap, so the whole station travels together. The fabric surface isn’t heat resistant, so keep the soldering iron off it; it’s for handling, assembly, flashing and repair.

Bertech’s everyday mat is a thick, single-layer ESD polymer with a textured finish that stops small parts sliding around. It sits at the higher-resistance end of the dissipative range, which drains charge gently and suits assembly, inspection, flashing firmware and plugging modules into breadboards. Like the high temperature kit it includes a wrist strap and ground cord, and it’s made in the USA. It isn’t rated for soldering heat, so pick the 2059T if the iron shares the bench.

The usual frustration with a wrist strap is that it won’t connect to what you have. StaticTek’s set ships a 6 ft coil cord with a 10 mm snap at the band and both a banana plug and a 4 mm alligator clip at the ground end, so it plugs into a mat’s banana jack, a ground cord or a bare chassis screw. The soft blue fabric band adjusts up to XL. It has fewer Amazon reviews than the big names, and the listing also sells multi-packs, so check the quantity.

Many cheap straps are too tight to wear for long, so they end up in a drawer. iFixit made this one with a wider band that adjusts up to XL, a coiled cord with the required 1 megohm resistance and an alligator clip. It’s simple, comfortable and backed by iFixit’s support, and it pairs naturally with their portable mat. The clip is the only connector, so there’s no banana plug or snap-to-mat option.

The SWS100 has been the go-to inexpensive strap for years, with a very long review history. It uses a static dissipative band, a 6 ft grounding cord and an alligator clip that grabs a grounded chassis, a mat’s ground point or a bench ground screw. Keep one in your laptop bag or toolbox for the times you flash or swap a module away from your main bench. It has no snap or banana plug, and the band is a basic elastic.

9. Desco 13415 Statshield Metal-In Shielding Bags (4 x 6 in)

A mat protects parts while they’re on the bench; a shielding bag protects them everywhere else. Desco’s Statshield bags are transparent metal-in shielding bags with an open top, and the 4 x 6 in size fits ESP32 modules, sensor breakouts, small dev boards and spare chips. Unlike pink anti-static poly bags, which only avoid generating charge, a metallised shielding bag blocks an external discharge from reaching what’s inside. Fold the top over or tape it shut. Check the listing for the pack quantity.

Soldering and rework bench

The Bertech 2059T kit, upgraded with an SCS 2214 strap.

Tight budget

The Kaisi silicone kit covers mat, strap and ground in one box.

Working away from the bench

The iFixit Portable Mat, plus a StarTech SWS100 as a spare.

Prototyping without an iron

The Bertech 1059 mat with a StaticTek WO5 or iFixit strap.

Do I really need ESD protection for ESP32 dev boards?

For plugging jumpers into a DevKit, the risk is low because the board has some protection. It matters once you handle bare ESP32 modules, sensor breakouts, MOSFETs or boards you’re soldering and reworking, and more in dry winter air. A mat and strap cost less than a reel of modules.

Why does a wrist strap need a 1 megohm resistor?

It lets static drain slowly instead of in a damaging spike, and it limits current through you if your hand touches a live conductor. A strap with a bare wire and no resistor is not a safety device.

Where do I connect the ground cord?

Usually to the centre screw of a properly grounded outlet cover plate using the cord’s ring lug, or with a grounding plug that only connects to the earth pin. Connect the mat and wrist strap to the same common point. Never use a gas pipe or the neutral pin, and check your outlet is actually earthed.

Can I put a powered ESP32 board on an ESD mat?

No. A dissipative mat is slightly conductive, so exposed pins on the underside of a powered board can leak current or misbehave. Work on boards unpowered, or put a powered board on a non-conductive stand or its standoffs.

Are pink anti-static bags as good as shielding bags?

No. Pink bags only avoid generating static themselves. Silver or metal-in shielding bags, like the Desco Statshield, also block an outside discharge from reaching the part, so use them for storing and shipping bare modules.