Editing Omron B3K series (section)

==Variants==
===Romer-G===
Logitech Romer-G exist in both tactile damped (B3K-T13L), tactile ((B3K-T13L2) and a linear variant (B3K-L13L).
The top housing bears the Logitech "G" logo on two opposite sides, and the Omron logo on a third side. The bottom housing bears the part number.

The earliest variant was the tactile damped B3K-T13L, which can also be identified by having a blue housing whereas the others are black.
[[Damping]] is on both the down-stroke and up-stroke, by having a pair of plastic prongs on the slider (called "elastic touch piece" in the patent). These collide with features of the base (downstroke) and lid (upstroke) to absorb impacts. Specifically, the prong hits a raised area in the base on the way down, and ridges in the lid on the way up. The patent describes the product as a "silent type switch having small operation sound and return sound".
The key travel for the damped switches is rated at 3.0 mm, but has been measured to between 3.06 and 3.17 mm in reality.

The Romer-G variants with black top housing (B3K-T13L2, B3K-L13L) lack the damping prongs, and have instead more key travel: rated at 3.2 mm.

Logitech had applied for the "ROMER G" trademark on 23rd June 2014.<ref name="romerg2" />

===Das Keyboard Gamma-Zulu===
The Das Keyboard Gamma-Zulu (B3K-T135M) are tactile and undamped with 3.5 mm key travel. The top housing is black, carrying the Omron logo and the Das Keyboard symbol on different sides.

They were manufactured by Omron for Das Keyboard ([[Metadot]]), starting with the [[Das Keyboard#Das Keyboard 5Q|Das Keyboard 5Q]] which was announced on a Kickstarter page in July 2016 with estimated delivery in Dec 2016.<ref name="das5qkickstarter">Kickstarter &mdash; [https://www.kickstarter.com/projects/1229573443/das-keyboard-5q-the-cloud-connected-keyboard/description Das Keyboard 5Q: The Cloud Connected Keyboard by Das Keyboard]. Retrieved 2016-07-02.</ref>
When announced, the estimated lifetime of the switch has also been upped to 100 million actuations, compared to 70 million for the first Romer-G.

===Creative Labs PRES===
Creative PRES switches (''Perceive-React-Execute Switches'') <!-- :rolleyes: -->
were introduced with the ''Sound BlasterX Vanguard K08'' keyboard. 

===Observed variants===
All variants have officially a pre-travel of 1.5 mm.

{| class="wikitable variants-table"
! !!Brand Name!!Part #!!Colour<br>(Top/Slider)!!Type!!Total Travel!!Actuation force!!Tactile force!!Total force!!Rated lifetime
|-
|[[File:Logitech Romer-G blue -- variants table.jpg|175px]]
| rowspan="3" |Logitech Romer-G
|B3K-T13L||Blue/Clear||Tactile Damped||3.0 mm
| rowspan="3" |45 gf
| || ||70 M
|-
|[[File:Logitech Romer-G black -- variants table.jpg|175px]]||B3K-T13L2||Black/Clear||Tactile||3.2 mm||55 gf|| ||
|-
| ||B3K-L13L||Black/Grey||Linear||3.2 mm|| || ||
|-
| ||Das Keyboard Gamma-Zulu||B3K-T135M||Black/Clear||Tactile||3.5 mm||45 gf||55 gf||80 gf||100 M
|-
| ||Creative Labs PRES|| ||Transp/Clear||Tactile||3.5 mm|| || || ||70M
|}