The best replacement for e-grip is response trigger.

The best alternatives to e-grip are rated as following:
★★★★★  response trigger
★  e-trigger

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Speaking about e-grip, one probably shouldn't forget about selector switch - a5.

Other search terms related to e-grip and their ratings are:
★★★★★ selector switch - a5
You have in mind a companion for e-grip and it is not yet here? Propose!



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e-grip
response trigger
e-trigger