Perun ETU ++ MosfetPerun ETU ++ Mosfet for G&G electronic trigger units. This is a wicked upgrade that unlocks so many premium features without having to open the gearbox! ETU++ is a dedicated replacement for G&G ETU electronic board. It enhances your trigger unit by adding many new, useful features. Simply disconnect the stock electronic board and plug in ETU++. The stock trigger unit (switch set) is retained, so there is no need to open the gearbox. Works with any G&G