1a:T52c,Some of the models are designed for rigid materials and others for flexible ones. The models materials are not interchangeable, so pay attention to the file names. If you have any request on the design just ask me.
For other phone cases check this
Here is the explanation of the files names:

Flex: made for elastic filaments like TPU. Not tested.
Rigid: made for rigid (non-elastic) filaments like PLA, ABS, HIPS, etc. The holes for the buttons are opened on the front side. Tested only on PLA.

I spend part of my time making these models, letting them available and free for everyone. If you want to support my work, you can contribute with me here:

1b:T47d,'720':3A 'abs':77B 'and':15B,107B 'any':36B 'are':10B,23B,85B 'ask':42B 'attention':28B 'available':106B 'buttons':84B 'can':119B 'case':5A 'cases':47B 'check':48B 'contribute':120B 'design':40B 'designed':11B 'elastic':61B,73B 'etc':79B 'everyone':110B 'explanation':53B 'filaments':62B,74B 'file':31B 'files':56B 'flex':58B 'flexible':18B 'for':12B,17B,44B,60B,69B,82B,109B 'free':108B 'front':89B 'have':35B 'here':50B,123B 'hips':78B 'holes':81B 'i':95B 'if':33B,111B 'interchangeable':25B 'is':51B 'just':41B 'letting':104B 'like':63B,75B 'lumia':2A 'made':59B,68B 'making':101B 'materials':14B,22B 'me':43B,122B 'models':9B,21B,103B 'my':99B,116B 'names':32B,57B 'nokia':1A 'non':72B 'non-elastic':71B

Found 10 3D-models for “RM8” across many websites

RM85 Rear Caliper Guard

RM85 Rear Caliper Guard V2

RM85 Rear Caliper Guard OEM Style V2

RM85 Rear Caliper Guard OEM Style V3

70s - 90s RM80 & RM85 Number Plate Cadillac Crew Style

Air Gun / Air Rifle Silencer Moderator Suppressor 1/2" UNF Thread

Modular Air Gun / Air Rifle Silencer Moderator Suppressor

Nokia Lumia 720 rm885 case

Airgun moderator 1/2" UNF (.22)

Walther RM8 loading tool