# Frequently Asked Questions Get to know the ProStraps Sleeves better through these frequently asked questions. # ProStraps FAQ · **What is the difference between \[MK2 Standalone for bare controllers\] and \[MK2 Upgrade for controller mounts\]?** For certain HMDs such as Quest 3, our ProStraps used with the controller mount replace the existing insert layer and are never attached directly to the controller. Due to ergonomics, the design has to be different for use with or without the controller mount. Standalone for bare controllers is for use with just the controllers, and does not work with any of our other products. Upgrade for controller mounts goes into your controller mount, and becomes a part of the controller mount, which combined does work with our other products. We call this new design MK2 respectively. **We only offer MK1 or MK2 for any HMD. Quest Pro, Quest 3, Quest 3S only have MK2.** · **What does \[MK1 model usable with and without controller mounts\] mean?** This is the original design we now call MK1. Specifically, it installs on the controller itself at the top. At the bottom, it installs to the controller mount, or to the bottom of the controller. You can freely change it from installed to the bottom of the controller mount to the bottom of the controller or vice versa without needing another product, unlike MK2. **We only offer MK1 or MK2 for any HMD. Quest 1, Rift S, Quest 2, and Pico 4 only have MK1.** · **I bought a new headset and want controller mounts for them. Do I need to buy ProStraps again?** The ProStraps for controller mounts can be reused, and you only have to buy the respective attachment found on [this](https://www.protubevr.com/en/595-prostraps "this (https://www.protubevr.com/en/595-prostraps)") page. · **I got ProStraps for Quest 3 and want to use them both with and without the controller mounts. Do I have to buy them again?** Go to [this](https://www.protubevr.com/en/prostraps/560-7895-prostraps-top-attachement-quest-3.html "this (https://www.protubevr.com/en/prostraps/560-7895-prostraps-top-attachement-quest-3.html)") page and select the one you don't already have. If you already have the one for controller mounts, you want the one for bare controllers. This is not for a pair, you will need to buy 1x for Left hand, and 1x again for Right hand. **Using it this way requires moving the ProStrap cushion pad from one to the other each time, but saves you money.** · **Where are ProStraps for Rift CV1?** We never made or sold ProStraps for Rift CV1. Afaik, ProStraps released in second half of 2020 for Rift S & Quest 1, with Quest 2 releasing later that year. If you want to use our ProStraps with Rift CV1 you would need to DIY how the strap attaches to the top of the controller. Could be as simple as looping something around the tracking ring, for the top part of the strap to attach to.