The two main buttons (M1 and M2) sit on tiny switches inside the shell. The switch determines how the click sounds, how heavy it feels, how fast the signal reaches your PC, and how long the mouse will last before developing the dreaded double-click bug.
Mechanical switches — how they work
A mechanical click switch has a tiny metal contact leaf that bows under pressure until it snaps against a second contact. The snap closes the electrical circuit, the mouse's firmware sees the contact, and a click is sent to the PC. Releasing the button lets the leaf spring back open.
The 'click' you hear is the tactile snap of the leaf, not the actual electrical contact. That snap is also the source of mechanical switches' biggest weakness: the contacts can wear, oxidize, or bounce, eventually causing the switch to register two clicks for one physical press — the double-click bug.
Common mechanical switch brands
- Omron D2FC (China-made)
- The most-used mainstream switch for over a decade. Crisp medium-weight click. Rated 20M or 50M, often develops double-clicks earlier than the rating suggests due to contact oxidation. Found in many older Logitech, Razer, and Glorious mice.
- Omron D2F (Japan-made)
- Premium variant of the D2FC. Heavier, more deliberate click, longer real-world lifespan. Used in higher-end and audiophile mice. Often hand-swapped by enthusiasts.
- Kailh GM 8.0 / 4.0
- The current default in many mid-range mice. 80M (8.0) or 40M (4.0) cycles. Snappier and lighter than Omron, with less side-to-side wobble in the button cap.
- Huano Blue / Pink / Black Shell
- Used by Endgame Gear, Pulsar, VAXEE, Razer DeathAdder V3 Pro Faker Edition, and Wooting mice. Deep, soft, satisfying click. The Blue Shell is heavier, Pink is lighter; both are praised for feel but have a less defined tactile bump than Kailh.
- TTC Gold
- Used in some Glorious and Lamzu mice. Light, crisp, with a clear tactile snap. Sits between Omron and Kailh on the feel spectrum.
Optical switches — how they work
An optical switch replaces the metal contact with a beam of infrared light. Pressing the button drops a small physical flag through the beam; breaking the beam triggers the click. There's no metal-on-metal contact at all.
- No double-click bug — there's no electrical contact to wear or bounce.
- Faster signal time — no need to wait for a debounce window (more on that below), because the optical signal can't bounce.
- Different feel: the tactile snap is mechanical (a tiny spring), but the 'click' you hear and feel is purely the physical button, not the switch closing. Some find this less satisfying.
- Rated for 70–100 million clicks, usually outlasting the rest of the mouse.
Optical switch brands
- Razer Optical (Gen 2 / Gen 3)
- Razer's in-house design. Crisp, very fast (~0.2 ms switch latency), in Viper, DeathAdder, and Basilisk Pro lines.
- LK Optical (Light Strike)
- Originally for keyboards; LK 2.0 used in Glorious Model O 2 Wireless and the Endgame Gear OP1 8K. Light, fast, slightly mushy compared to mechanical.
- TTC Optical
- Common in budget Chinese mice (Attack Shark, Aula, Delux). Quality varies; usually decent for the price.
Pre-travel and post-travel
- Pre-travel
- Distance the button moves before the switch fires. Lower is faster — less wasted motion before the click registers. Modern flagships are well under 1 mm.
- Post-travel
- Distance the button continues moving after the click. Lower is crisper — your finger stops where the click happens, not in a mushy follow-through.
- Side play
- How much the button rocks side-to-side before it depresses. Less is better; modern designs use built-in alignment to keep this under ~0.05 mm.
Debounce time
When a mechanical contact closes, the metal physically bounces for a few hundred microseconds before settling. Without filtering, the mouse would see this as multiple clicks. Firmware adds a debounce window — usually 4–12 ms — during which extra contact events are ignored.
Some mice (Logitech, Razer, Pulsar) let you adjust debounce in software. Lower debounce means faster click registration, but if you go too low the switch's natural bounce can produce false double-clicks. Optical switches don't bounce, so they can ship with effectively 0 ms debounce — which is part of why optical mice often feel snappier even when the rest of the latency is similar.
Side buttons, scroll wheel, and DPI button
Side buttons usually use the same Kailh GM, TTC, or Huano switch family as the main buttons but in a smaller form factor. The scroll wheel button (M3) uses a tactile dome switch — these wear at a similar rate to M1/M2. The DPI cycle button is usually a simple tact switch and never fails.
Does any of this actually matter for aim?
Click latency from a modern mechanical mouse with a 4 ms debounce is around 4–8 ms. From an optical switch, it's closer to 1–2 ms. On a 240 Hz monitor with a 4.2 ms frame, that's a difference of roughly one frame. Detectable on instruments, marginal in actual play. For most people the larger factor is durability — an optical or premium-mechanical mouse is much less likely to develop a double-click bug a year in.
More mice guides
- Mouse sensors, explained from scratchWhat DPI, polling rate, IPS, and lift-off distance actually mean — and which sensor names matter when comparing modern gaming mice.
- Mouse shapes and how to read themSymmetrical vs ergonomic, hump position, length and width, and the shape lineages (EC, FK, IE/IO, DA, ZA) that most modern mice descend from.
- Palm, claw, fingertip — finding your gripThe three textbook grip styles, hybrids in between, and how to match grip to shape, sensitivity, and intended game.
- Wireless vs wired mice — the latency myth, properlyWhat 2.4 GHz dongles actually do, why Bluetooth is not the same, battery life trade-offs, and when wired still wins.