I recently decided to do a PC build for my niece. The Phanteks P300 case came without a cover for the expansion slots--which is alarmingly common. Fortunately, my personal rig has a Phanteks P350X, with the cover--used it as a template to create a replacement.

I designed it for use with 6x3mm magnets, but also added holes for thumb screws (if needed).

Measurements taken with digital callipers.

Monoprice

Maker Select Plus

Doesn't Matter

Yes

0.15

50%

My MP Maker Select Plus also has the following upgrades;

• Borosilicate Glass Heat bed (200x200x3mm)
• Micro Swiss All Metal Hotend with Slotted Cooling Block
• Micro Swiss CNC Machined Lever and Extruder Plate (flexible mod OTTB)
• YOTINO 3D Printer Thermistor NTC 3950 100k Thermistor
• BIQU TL-Smoother