Decadriver

The Decadriver (ディケイドライバー) is a belt that gives Tsukasa Kadoya the ability to become Kamen Rider Decade, based around the Rider Cards. It was created alongside the Ride Booker, as well as Diend's Diendriver, by scientists of Dai-Shocker, which included Joji Yuki.

The Decadriver and Ride Booker were created for Tsukasa's use, having been the Great Leader of Dai-Shocker before losing his memory. However, both items were abandoned and left to corrode before they were found by Natsumi Hikari amongst rubble during the destruction of the worlds. Recognizing them from her dream of Decade, she gave them to Tsukasa who was trapped in another dimension, with the items being restored as they passed through the dimensional wall. Taking the Kamen Ride: Decade card from the Ride Booker, Tsukasa inserted it into the Decadriver, transforming for the first time to defeat the rampaging monsters.

Functionality
By inserting a card into the Decadriver, Decade can invoke the cards' abilities. In Complete Form, the Decadriver is moved to the right side of his belt where Decade inserts his Final Attack Ride Cards and activates them by touching the Decadriver's window.

As seen in , along with Blade's Blay Rouzer and Ryuki's Drag Visor, the Decadriver is also compatible with at least some of the used by the. This is shown when he is given the Reflecloud card by to counter Kani Lazer's beam attack.

The Complete Selection Modification Decadriver was released in February 2015. Mark Okita, who provides the voice for the Decadriver, was invited to record new sounds for existing Rider Cards, including Kamen Ride cards for Decade's first six Phase 2 Heisei successor Riders from Double up to Drive.

Coincidentally, three years later following the release of the CSM Decadriver, Tsukasa would later appear with the Neo Decadriver (ネオディケイドライバー), a magenta-colored version of his belt that would allow him to transform into his successors from Double to Build. Additionally, the Driver now includes the aforementioned Riders' symbols on it (except for himself and Zi-O).

Form Changes
When Kamen Rider Decade transforms into the previous Nine Heisei Riders using the Kamen Ride Cards, he still appears sporting the Decadriver in the place of their respective belts, to use his various Attack Ride cards. However when he disguised himself as Kamen Rider Ichigo, the Decadriver took on the appearance of Rider 1's Typhoon belt, unlike other Kamen Rides where the Decadriver is still present. It changed back when the Decadriver/Typhoon was struck by Captain Marvelous as Akarenger. It is unknown if this is a property of the card itself or a yet-undemonstrated ability of Decade's.

Jumbo Decadriver
In the summer film, Decade is transformed by a Decade Final Form Ride Card into the Jumbo Decadriver (ジャンボディケイドライバー), a larger version of the Decadriver which is worn by a Kamen Ride Card-summoned Kamen Rider J to transform into Decade Complete Form Jumbo Formation (ジャンボフォーメーション). This form is identical to the usual Complete Form, apart from the fact that Decade is now many times larger, and wears the Decadriver on the front of his belt, with no K-Touch.

The name of the Decadriver is misspelt as "Decaderiver" on this card.

Announcements

 * Change announcement: KAMEN RIDE
 * Form Change announcement: FORM RIDE
 * Attack announcement: ATTACK RIDE
 * Rider Form change announcement: FINAL FORM RIDE
 * Final attack announcement: FINAL ATTACK RIDE
 * Decade Complete announcement: FINAL KAMEN RIDE
 * Decade Complete Jumbo announcement': FINAL KAMEN ATTACK FORM RIDE

Portrayal
The voice of the Decadriver, as well as the Diendriver, K-Touch, and Rider Battle tournament announcer in All Riders vs. Dai-Shocker, is provided by Mark Okita (マーク・大喜多).

DX Decadriver's unused sound
In DX Decadriver, it has "FINAL RIDE", and "RIDE" announcements but they are never used.

Complete Selection Modification Decadriver's unused sound
The CSM features the post-Decade Riders transformation sound, from Double to Drive, the primary Riders final form announcement and their transformation sound, as well as Diend's Rider Cards. The use of Diend's cards and a slip of paper that came with the CSM Decadriver with Diend's logo and the words "Coming Soon" hinted at the release of the CSM Diendriver and belt.