Gateron KS-9 Pro 2.0 Linear switches has less wobble, smoother feeling, and better STOCK sound. 
So... the real question is... what's the difference between these PRO 2.0s versus the regular/milky variants? Well, it's straight up a revamped version of the older switches. 
They come with an improved transparent housing, and they are for those who are just looking for a good stock switch to use for an AFFORDABLE price. Can't beat this!

They all come pre-lubed from factory. They are very light, and can be lubed over.
KS-9 Yellow Pro 2.0


Linear

2.0±0.6mm Pre-Travel
4mm Total Travel Distance
50g Operating Force
67g Bottom Out
15.4mm Spring
MX Switch
3/5-pins

Lightly Factory-lubed


KS-9 Brown Pro 2.0


Tactile

2.0±0.6mm Pre-Travel

4mm Total Travel Distance
55g Operating Force
50g Bottom Out
20.5mm Spring
MX Switch
3/5-pins
Lightly Factory-lubed


Here is a guide on how many switches you'll need for different keyboard sizes (The guide is a reference, but some keyboards market a certain layout even though they require a few more or fewer switches. Always order a few more if you're unsure):

120 - full size
92 - TKL
80 - 75%
70 - 65%
65 - 60%
45 - 40%

Selling in quantities of 1.

- Gateron KS-9 Pro 2.0 Linear switches have less wobble, smoother feeling, and better stock sound
- Revamped version of older switches with improved transparent housing
- Affordable price for those looking for a good stock switch
- Comes pre-lubed from factory
- KS-9 Yellow Pro 2.0: Linear, 50g operating force, 67g bottom out, lightly factory-lubed
- KS-9 Brown Pro 2.0: Tactile, 55g operating force, 50g bottom out, lightly factory-lubed
- Guide provided for number of switches needed for different keyboard sizes
- Selling in quantities of 1

Gateron KS-9 PRO 2.0 Switches

Gateron KS-9 Pro 2.0 Switches uses an improved top housing by being more transparent and including a light guide pole in the top housing light hole. It still achieves what it sets out to do by improving on the KS-3 switches with a more balanced top out and reduced stem wobble.
Gateron KS-9 Pro 2.0 Switches Features: 18 included in each pack
MX Switch
3-Pin, Plate Mount
Pre-lubed
Available in: KS-9 Yellow Pro 2.0 (5-Pin)
KS-9 Black Pro 2.0 (5-Pin)
KS-9 Brown Pro 2.0 (5-Pin)
KS-9 Silver Pro 2.0 (5-Pin)
KS-9 Red Pro 2.0 (5-Pin)
KS-9 White Pro 2.0
KS-9 Blue Pro 2.0 Type Pre-Travel
Total Travel
Operating Force
Bottom-Out
Spring
Price Yellow
Linear 2.0±0.6mm 4.0mm
50g
67g
15.4mm
$0.23/switch Black
Linear 2.0±0.6mm 4.0mm
60g
70g
15.4mm
$0.23/switch Brown
Tactile 2.0±0.6mm 4.0mm
55g
50g*
20.5mm
$0.23/switch Silver
Linear 1.2±0.3mm 3.4+0/-0.4mm
43g
50g
22.0mm
$0.28/switch Red
Linear 2.0±0.6mm 4.0mm
45g
50g
20.5mm
$0.23/switch White
Linear 2.0±0.6mm 4.0mm
38g
45g
20.0mm
$0.28/switch Blue
Clicky 2.3±0.6mm 4.0mm
60g
60g*
15.4mm
$0.23/switch *Operating to Bottom-Out
Includes: 18 Gateron KS-9 Pro 2.0 Switches

Product: Gateron KS-9 Pro 2.0 Switches

Features:
- Improved top housing with light guide pole
- Balanced top out and reduced stem wobble
- 18 switches included in each pack
- Available in 7 types: Yellow, Black, Brown, Silver, Red, White, and Blue
- Pre-lubed
- 3-Pin, Plate Mount

Switch Types:
- Yellow: Linear, 50g operating force, $0.23/switch
- Black: Linear, 60g operating force, $0.23/switch
- Brown: Tactile, 55g operating force, $0.23/switch
- Silver: Linear, 43g operating force, $0.28/switch
- Red: Linear, 45g operating force, $0.23/switch
- White: Linear, 38g operating force, $0.28/switch
- Blue: Clicky, 60g operating force, $0.23/switch

Note: Brown and Blue switches have different operating and bottom-out forces.

Gateron KS-9 Pro 2.0 Switches

Gateron KS-9 Pro 2.0 - Brown are the most recent update to Gateron's popular brown switches. They feature improved molds with better tolerances and smoothness. The top housing is now clear with a light guide dome to assist with RGB diffusion. The switches are lightly pre-lubed from factory for a solid experience without modifications. Switches are sold in packs of 10.
Quantity 1 = 10 switches. Specifications: Tactile
Spring: 50g bottom-out / 55g actuation, 20.5mm spring 4.0mm travel / 2.0mm actuation
PCB mount (5-pin) Lightly pre-lubed from factory
Manufactured by Gateron

- Gateron KS-9 Pro 2.0 - Brown switches are the latest update to Gateron's popular brown switches
- Improved molds with better tolerances and smoothness
- Clear top housing with a light guide dome for RGB diffusion
- Lightly pre-lubed from factory for a solid experience without modifications
- Sold in packs of 10 switches
- Tactile with a 50g bottom-out / 55g actuation spring and 4.0mm travel / 2.0mm actuation
- PCB mount (5-pin)
- Manufactured by Gateron

Gateron KS-9 Pro 2.0 - Brown

Gateron KS-9 Pro 2.0 - Black are the most recent update to Gateron's popular black switches. They feature improved molds with better tolerances and smoothness. The top housing is now clear with a light guide dome to assist with RGB diffusion. The switches are lightly pre-lubed from factory for a solid experience without modifications. Switches are sold in packs of 10.
Quantity 1 = 10 switches. Specifications: Linear Spring: 70g bottom-out / 60g actuation, 15.4mm spring 4.0mm travel / 2.0mm actuation
PCB mount (5-pin) Lightly pre-lubed from factory
Manufactured by Gateron

- Gateron KS-9 Pro 2.0 - Black are the latest update to Gateron's black switches
- Improved molds with better tolerances and smoothness
- Clear top housing with a light guide dome for RGB diffusion
- Linear switches with 70g bottom-out / 60g actuation spring and 4.0mm travel / 2.0mm actuation
- PCB mount (5-pin)
- Sold in packs of 10 switches
- Lightly pre-lubed from factory for a solid experience without modifications

Gateron KS-9 Pro 2.0 - Black

Gateron KS-9 Pro 2.0 - Yellow are the most recent update to Gateron's popular yellow switches. They feature improved molds with better tolerances and smoothness. The top housing is now clear with a light guide dome to assist with RGB diffusion. The switches are lightly pre-lubed from factory for a solid experience without modifications. Switches are sold in packs of 10.
Quantity 1 = 10 switches. Specifications: Linear Spring: 67g bottom-out / 50g actuation, 15.4mm spring 4.0mm travel / 2.0mm actuation
PCB mount (5-pin) Lightly pre-lubed from factory
Manufactured by Gateron Sound Tests:

- Gateron KS-9 Pro 2.0 - Yellow switches are the latest update to Gateron's popular yellow switches.
- Improved molds with better tolerances and smoothness.
- Clear top housing with a light guide dome for RGB diffusion.
- Linear switches with 67g bottom-out / 50g actuation, 15.4mm spring, 4.0mm travel / 2.0mm actuation, and PCB mount (5-pin).
- Sold in packs of 10 switches.
- Lightly pre-lubed from factory for a solid experience without modifications.
- Manufactured by Gateron.
- Sound tests available.