Replacement Razors SL Shock Absorbers. These also work great as a replacement shock absorber for your Salomon skates. Take a look inside, it's either crumbled away or melted to the bottom of the boot.

Compatibility
The sizing should be consistent across all skates but some minor modifications may be needed if using in other skates as below:

Razors SL/Shift
No modification is required if purchased correct size for skates. The square slots into the base of the skates. 

Salomon
Salomon skates used a small "nib" to slot their shock absorbers into place. You can either take this part out of the skate or create a corresponding hole at the bottom of the shock absorber for perfect alignment. You will also need to shave/chop the square at the bottom of the shock absorber for a more snug fitment. 

Other brands
Modification is highly likely to be required for a snug fitment. May not be recommended if using a raised-heel boot. 

Sizing 
XS: UK1-4 / US2-5
Small: UK5-6 / US6-7
Medium: UK7-8 / US8-9
Large: UK9-10 / US10-11
XL: UK11-UK12 / US12-13