All Mill-Max sockets have been directly purchased through either Digikey or Mouser. We buy these in bulk quantities - the discounts we receive from this go directly towards reducing your costs!

If you're into modding your keyboard (which you probably are since you're here), there are many reasons for wanting to remove your switches easily and often (e.g., change to different switches, re-lube switches, re-lube stabs).

Without hotswap sockets, you'll have to resort to desoldering and resoldering your switches, which can be quite time-consuming. Repeated desoldering can also increase wear to your PCB. With hotswap sockets, you solder them on once and then you're good to go!

0305:

• Longest tail (3.94mm), which may cause fitment issues with low-profile cases. However, these sockets will still work with a large majority of keyboards.
• Largest top lip (0.64mm), which causes switches to sit at a raised height. This can change the sound and feel of the keyboard and also may cause issues with seating switches into the mounting plate.
• Contact finish is tin, which has worse corrosion resistance than gold.
• Very affordable.

7305:

• Shortest tail (2.67mm), which ensures compatibility with low-profile cases. However, this also means they are much easier to mess up during installation by accidentally flooding them with solder.
• Smaller top lip (0.36mm), which means your switches will sit a bit more naturally with the PCB. Less height is better here, since we don't want the sockets to interfere with the switch sound and feel. Less height also means better seating with switches into the mounting plate.
• Contact finish is gold, which has better corrosion resistance than tin.
• Mid-range price.

3305:

• Specifically designed for keyboards. This is the 3305-1 variant, which we believe provides the best of both worlds with its size.
• Perfect tail length (3.30mm), which is short enough to avoid fitment issues but long enough to still provide ease of installation.
• Smallest top lip (0.25mm), which means your switches sit as flush as possible to the PCB. This is greatly desired, since your switches will sound and feel nearly identical compared to having them traditionally soldered in.
• Contact finish comes in tin and gold options. Please note that the tin option still features a gold finish in the interior portion of the socket. Therefore, the difference between the two 3305 finishes is primarily aesthetic.
• Costs the most out of the three.

An already hotswappable PCB most likely comes installed with Kailh sockets. We'll list some differences between Mill-Max sockets and Kailh sockets:

• Quality: Mill-Max sockets are rated for ~1000 cycles, whereas Kailh sockets are rated for ~100 cycles. Even if you aren't planning on swapping this amount of times, the ratings can be indicative to the quality difference between the sockets.
• Size: Kailh sockets are much bulkier on the bottom. This can possibly interfere with case standoffs.
• Switch Seating: Mill-Max sockets have a top lip, whereas Kailh sockets sit more flush with the PCB. This lip is undesirable, as it slightly affects how your switches sit and sound. Mill-Max 0305 sockets have a significant lip, 7305 sockets have a bit of a lip, and 3305 sockets have the smallest lip out of the three.

We've been there before. You might find these tips helpful:

• Use leaded solder wire (at your own risk) from a reputable brand, such as Kester or MG. Personally, we're fans of using Kester 44. High quality leaded solder not only makes the soldering easier and more consistent, but in our experience, it can also help with the visibility of solder. This can help prevent solder spilling into your sockets since you can actually see where your solder is flowing.
• Use thinner solder wire. This allows for greater control and decreases the likelihood of getting solder in places you don't want. We recommend 0.5mm (0.02") over the oft-recommended 0.8mm (0.032").
• Use tape to hold your sockets in place instead of using your switches. This way - if solder does enter sockets, it won't have a chance of ruining your switches' pins. We also find taping to be a faster method. Ensure the tape fully holds your sockets in place before soldering. Heat-resistant tapes (such as Kapton) may help with this process.